Zbigniew of Poland
|Prince of Poland|
Portrait by Leonard Chodźko.
|Predecessor||Władysław I Herman|
|Successor||Bolesław III Wrymouth|
8 July 1113 (?)|
Tyniec Abbey, Tyniec (?)
|Father||Władysław I Herman|
Zbigniew (also known as Zbygniew; ca. 1073 – 8 July 1113?), was a Prince of Poland (in Greater Poland, Kuyavia and Masovia) during 1102-1107. He was first-born son of Władysław I Herman and probably Przecława, a member of the Prawdzic family.
Zbigniew was considered illegitimate, and after the birth of his half-brother Bolesław was destined to the Church. At the end of the 11th century, when the real power in the country was by the Palatine Sieciech, the opposition of some Silesian magnates caused the return of Zbigniew to Poland and forced Władysław I his recognition as his successor. The intrigues of Sieciech and Władysław I's second wife Judith Maria caused that Zbigniew and his younger half-brother became allies, and both at the end forced their father to divide the country between them and the exile of the Palatine.
After the death of his father, Zbigniew obtained the northern part of the country as an equal ruler with Bolesław. However, soon erupted the conflicts between them, because Zbigniew, as the eldest one, considered himself the rightful and sole heir of Poland. He began to search allies against Bolesław. During 1102-1106 took place a fratricidal war for the supremacy, in which Zbigniew suffered a complete defeat and was forced to go into exile in Germany. Under the pretext of restoring him, in 1109 Emperor Henry V invaded Poland, but was defeated at Głogów.
In subsequent years, Boleslaw failed to defeat the neighboring Bohemia, and in 1111 he had to make peace with them and his overlord, the Emperor. One of the conditions of Henry V was the return of Zbigniew to Poland, where he received a minor domain. For unknown reasons, shortly after his return, Zbigniew was blinded, and then he died.
Following 15th-century reports, Władysław I Herman married with a Polish woman, a member of the Prawdzic family. This union was performed ca. 1070 under the Slavic rites without a church ceremony. Some medievalists argue that the marriage, although made under old Pagan rites, was lawful. They indicate that only at the end of the 12th century, the Papal legate Peter of Capua, who stayed in Poland during 1197, ordered that only the marriages performed under the Church rites (Latin: matrimonium in facie ecclesie contrahere) would be considered as legitimate, following the writings of the Rocznik krakowsk.
The exact birth date of Władysław I Herman's first-born son is unknown. According to Oswald Balzer, Zbigniew was born in the first half of the 1070s. Gerard Labuda agrees with a birth time during the first years of the 1070s. Roman Grodecki thought that Zbigniew's birth took place specifically around 1073. Kazimierz Jasiński believed in a birth date between 1070 and 1073.
Zbigniew's legitimacy was questioned in the later years of his life. To eliminate his pretensions to the throne he was declared the son of Władysław I's concubine. Despite this Zbigniew grew up in Władysław I's court and in the absence of others, was recognized as his father's heir.
In 1079 after his older brother Bolesław II the Generous was deposed, Władysław I became in the ruler of Poland. By this time he had probably already had Masovia as his own separate district. According to historians, the new ruler was quickly noted as incompetent, and the population began to miss the achievements of the exiled Prince. In 1080, Władysław I married Princess Judith, daughter of Duke Vratislaus II of Bohemia; Przecława, his first (but unrecognized according to the Church) wife was then banished from court. The elevation of his father to the Princely throne, the departure of his mother, who was sent with her family meant for young Zbigniew his removal from the first place in the succession. Around 1086 Władysław I's rule in Poland was threatened by the coronation of his father-in-law Vratislaus II as King of Bohemia and Poland, who at the same time concluded an alliance with King Ladislaus I of Hungary.
Władysław I's legitimacy was questioned by the supporters of the exiled Bolesław II and his only son and rightful heir, Mieszko Bolesławowic. Afraid of losing his position, in 1086 Władysław I recalled his nephew (and his mother) from their Hungarian exile. Mieszko received the district of Kraków and later married (1088) with a Rurikid princess. These moves led the opposition to stop questioning the legality of Władysław I's rule. The situation was further complicated by the prince because he didn't have a legitimate son. Zbigniew, his first-born son, couldn't be considered as heir, because he was a product of a union not recognized by the Church.
Loss of Primogeniture
In 1086, Judith of Bohemia finally gave birth to a son, the future Bolesław III Wrymouth, and with this Zbigniew's situation changed dramatically. In that year, he was placed in the Canonry of Kraków, despite he was too young to be ordained a priest. This position was likely arranged by Judith of Bohemia to keep Zbigniew away from the line of succession. Dowager Duchess Maria Dobroniega, Zbigniew's paternal grandmother, guided his ecclesiastical studies. It's known that the first teacher of Zbigniew was Otto, who later became Bishop of Bamberg. In addition to the religion teachings, he taught him there dialectic, grammar and the works of Isidore of Seville. Due to his young age, Zbigniew hadn't received the customary priestly journey.
A few months after the birth of her son, Judith of Bohemia died. In 1089 Władysław I married again. The chosen bride was Judith Maria, sister of Henry IV, Holy Roman Emperor and widow of the ex-King Solomon of Hungary; she was renamed Sophia, perhaps to distinguish herself from Władysław I's first wife. Zbigniew's relationship with her was a cold one.
The position of Bolesław as legitimate heir was still threatened by Mieszko Bolesławowic, who was popular with the Polish aristocracy. This probably contributed with his death in 1089, allegedly poisoned by orders of Sieciech and Judith Maria. In that year, Zbigniew was sent to Saxony, thanks to the intrigues of his new stepmother. Once there he was placed in Quedlinburg Abbey, where Judith Maria's sister Adelaide was Abbess. Probably there was finally ordained a priest. With this Władysław I wanted to get rid of Zbigniew: if he became a monk, he would be rendered ineligible for the succession. With this actions Władysław I eliminates the two main pretenders of the throne, secured the inheritance of his legitimate son Bolesław and weakened the growing opposition against him.
Rule of Sieciech
During the stay of Zbigniew in Quedlinburg, his father Władysław I fell into dependence on his supporter, Count Palatine Sieciech. Probably thanks to him, the Prince gained his throne. Sieciech was also the first guardian of Bolesław, still a minor. In his intrigues to take over the control of the country, the Palatine was supported by the Prince's wife Judith Maria.
In 1090, Sieciech, with his militia, took control of Gdańsk Pomerania. Władysław I prevented further actions through fortification of major towns and burning of others. Several months later, a rebellion of the elite of Gdańsk restored their independence. In the autumn of 1091, Polish and Bohemian militia made a further but unsuccessful invasion of Pomerania which culminated in a battle at the Wda river.
During this time, the Polish policy was directed to Kievan Rus'. The Rurikid princes of the Rostislavich line, then in power in Russia, didn't recognise Polish sovereignty, and led a hostile policy against them (especially Prince Vasilko of Terebovlia, allied with the Kipchaks) by repeated invasions to Poland. Sieciech was installed as the effective ruler of Poland. He demonstrated this by minting his own coin and consolidated his position by appointing his supporters to the judiciary. The main ambitions of Sieciech were his lust for power and the desire to enrich himself. To achieve his objectives, he was able to use violent methods. The repressive actions of Sieciech (selling into slavery, removal from offices, sentences of exile) caused a massive political emigration from Polish territories to Bohemia.
Legitimization and division of the Polish state
Act of Legitimization
The consequence of Sieciech's actions was a growing opposition against his rule. In 1093, a group of powerful Silesian lords kidnapped Zbigniew and returned him to Poland. Initially, Zbigniew was protected by Magnus, the Castellan of Wrocław. Władysław I took this as a clear revolt against him. The knighthood, who supported Zbigniew, broke all negotiations with Sieciech and Władysław I when reached news about the disloyal behavior of some Hungairian knights, who abducted both Sieciech and Bolesław. This forced Władysław I to issue an Act of Legitimization which recognized Zbigniew as his son, member of the Piast dynasty and rightful successor.
By 1096, Sieciech and Bolesław had escaped from Hungary and launched an expedition against Silesia and Kujawy to override the Act of Legitimization. With complete determination, Zbigniew defied the advancing of Władysław I and Sieciech's troops. Despite the help of Pomeranian troops, Zbigniew was defeated at the Battle of Goplo. He was captured and imprisoned until the intervention of the Church secured his release on 1 May 1097 at the consecration of the rebuilt Gniezno Cathedral. At the same the Act of Legitimization was reinstated.
After being discovered the intrigues of Sieciech and Judith Maria to take the power, Zbigniew and Bolesław became allies. In 1098, both princes forced Władysław I to give them separate provinces. Władysław I conceded and made a formal division of his lands.
Zbigniew received Greater Poland (including Gniezno), Kuyavia, Łęczyca and Sieradz Land. Bolesław received Lesser Poland, Silesia, Lubusz Land and probably Sandomierz and Lublin in the Bug River (near Brześć nad Bugiem). Władysław I kept Masovia and its capital, Plock as well as major cities including Wrocław, Kraków and Sandomierz.
Exile of Sieciech
The division of Poland and the admission of Władysław I's as co-rulers worried Sieciech. He feared that this could weakened his position. According to historiography, remains unclear why Władysław I supported Sieciech rather than his sons. With the threat of war, Zbigniew and Bolesław renewed their alliance and prepared for war. This renewal was formalised by the magnate Skarbimir at the Wiec in Wrocław. It was then decided that nobleman Wojsław Powała (a relative of Sieciech) was removed as Bolesław's guardian and the organization of the expedition against the Palatine. In 1099 the opposing forces met in a battle at the river Pilica near Zarnowiec. Zbigniew and Bolesław prevailed. The defeated Władysław I agreed to permanently remove Sieciech from his position.
A few months later, Zbigniew and Bolesław attacked Sieciechów, where the Palatine was hidden. Surprisingly, Władysław I, with a little army came to aid Sieciech. In this situation, the princes decided to deposed their father. In a campaign to encircle Sieciech and Władysław I, Zbigniew marched against Masovia, where he took control of Płock, while Bołeslaw was directed to the South, where he could conquer Lesser Poland. However, Władysław I could predicted the maneuvers of his sons and directed his forces to Masovia. The definitive battle between both armies took place near Płock. Władysław I was defeated and forced to exile Sieciech from the country. Martin I, Archbishop of Gniezno. also took a major part in the disagreements between Władysław I and his sons. The Palatine left Poland around 1100-1101 and went to Germany. He returned to Poland a few years later, but he didn't play any political role. It may have been blinded. Władysław I died on 4 June 1102.
Struggle for supremacy (1102–1106)
The division of the country between Zbigniew and Bolesław III was maintained. Thus resulted in two separated districts over whom both princes exercised full government. From the lands of Władysław I, Zbigniew received Masovia (with Płock) and Bolesław III received Sandomierz. However, disputes began between both rulers over seniority. Zbigniew considered himself as the Senior ruler over Poland, where his rights were recognized by the society.
The provinces of Zbigniew and Bolesław III operated as separate states with their own internal and foreign policies leading to discord between the two rulers. In their districts the brothers allied with the local nobility, who gathered hoped that in the future their respective ruler will occupy the dominant position in the country. In terms of foreign policy, each of them looking for allies. Pomerania became in a contentious issue between them, because Bolesław III wanted to expand his domains in this territory and made military incursions for this purpose. By the other hand, Zbigniew was a strong opponent of his brother's politics. He wanted to keep with the northern neighbor a good economic and political relation. In one of the first organized expeditions to Pomerania by Bolesław III, he managed to turn back the knighthood, which enraged the junior ruler. However, this situation didn't last, because in the next few months the knights were again in favor of Bolesław's expeditions and venturing with him several times into the West (also into Prussia). In autumn of 1102 Wrymouth organized an expedition, where his Drużyna (army) captured Białogard.
In retaliation, the Pomeranians directed military actions against Zbigniew, who at that point allied with Bohemia and wanted in this way to pressure Bolesław III into stopping his fight with Pomerania. The junior prince, in counterweight, decided to make an alliance with Hungary and Kievan Rus', sealed with his marriage with Zbyslava, daughter of Grand Prince Sviatopolk II of Kiev in 1103. Zbigniew declined to attend the wedding, seeing in this union a directed threat against him. Thanks to bribery, Zbigniew urged Borivoj II of Bohemia to invaded Bolesław III's lands. Bolesław III, reacted by ravaging and looting the Pomeranian border regions and Moravia; after this, and after the a huge payment, Borivoj II ended his alliance with Zbigniew. The incursions in 1103 -unsuccessful battle for Kołobrzeg) and during 1104-1105 effectively destroyed Zbigniew's peaceful relationship with Pomerania.
In 1105, Zbigniew and Bolesław III agreed to reciprocal compromise in matters of foreign policy. However, with respect to Pomerania, the agreement (called the Tyniec Accord) failed. The following year, Zbigniew refused to help his brother in his fight against the Pomeranians. In retaliation, and with the help of his Kievan and Hungarian allies, Bolesław III attacked Zbigniew’s lands. In this way began a civil war whose primary objective was the elimination of Zbigniew's pretensions to the overlordship. The combined army took Kalisz, Gniezno, Spycimierz and Leczyca without difficulty. Bolesław III also captured Archbishop Martin I of Gniezno, the main ally of Zbigniew. In Łęczyca, through the mediation of the Bishop of Kraków, Baldwin, Zbigniew capitulated. Bolesław III became the 'High Duke of all Poland', and gained from Zbigniew the regions of Greater Poland, Kuyavia, Łęczyca and Sieradz Land. Zbigniew retained Masovia as a fiefdom.
End of Reign
In 1107 Zbigniew organized a rebellion against Bolesław III, who ordered to burn the fortress of Kurów in Puławy. He refused to do this, and Bolesław III used his rebellion and the failure to provide him with military support in his campaign against Pomerania as excuses to attack Zbigniew.
In the winter of 1107-1108, Masovia was attacked by the combined forces of Bolesław III and his Kievan-Hungarian allies. Zbigniew was forced to surrender and exile from the country. Since then, Bolesław III became in the sole ruler over all Poland. The actual transfer of power took place the year before (1107) when Zbigniew was still in Masovia; then he paid complete homage to his brother for his land. Initially, Zbigniew took refuge in Prague, where he found support in the local ruler, Svatopluk.
Claims against Bolesław III
The pretext for the Polish-German War in 1109 were the claims of the exiled Zbigniew, who seek justice, reparation and assistance in the recovery of his lost lands. Emperor Henry V gave an ultimatum to Bolesław III. He would abandon the expedition against him only if Zbigniew was restored with half of Poland under his rule, the formal recognition of the Holy Roman Empire as overlord and the payment of 300 pieces of fine silver as a regular tribute or provide 300 knights on military expeditions. The immediate cause of the war was the attack of Bolesław III against Bohemia in 1108 who thwarted the projected German-Bohemian expedition against Hungary. The answer to the aggressive policy of Boleslaw against Bohemia, was a retaliatory expedition by Henry V and his Bohemian allies. The claims of Zbigniew were treated by the Emperor secondarily.
Hostilities began in Silesia. Bolesław III was conducting a highly effective guerrilla war against the Holy Roman Emperor and his allies, and eventually he defeated the German Imperial forces at the Battle of Hundsfeld on 24 August 1109, although the existence of this battle is doubted by historians because it was first recorded about a century later. Sources don't provide information if Zbigniew took direct part in the expedition.
Blinding and death
In 1110, Bolesław III made an unsuccessful military campaign against Bohemia. His intention was to install yet another pretender on the Czech throne, Soběslav I, who sought refuge in Poland. During the campaign won a decisive victory against the Czechs at the Battle of Trutina on 8 October 1110; however, following this battle he ordered his forces to withdraw further attack against Bohemia. The reason for this is speculated to be the unpopularity of Soběslav I among Czechs as well as Bolesław III’s unwillingness to further deteriorate his relations with the Holy Roman Empire.
In 1111 a truce was made between the Duke Vladislav I of Bohemia and Bolesław III. Under the terms of this agreement, both Soběslav I and Zbigniew could be returned their homelands. Once in Poland, Zbigniew received a grant of land, probably Sieradz.
Bolesław III probably also agreed with the return of his half-brother as a result of pressure from the many supporters of the exiled prince in 1108, who according to the reports of Gallus Anonymus was surrounded to bad advisers (in this group unfavorable to Bolesław III was probably Martin I, Archbishop of Gniezno). Once in Poland, Zbigniew could claim the sovereignty over his previous domains at the instigation of this group. The first step towards this was his presence in the Advent ceremonial (which was forbidden to him by Bolesław after recognizing him as his overlord in Łęczyca in 1107), which is reserved only for rulers. Zbigniew arrived surrounded by attendants, being carried before him a sword. This could be perceived by Boleslaw III as an act of treason and caused a definitive breach in their relationship, under which Zbigniew was the vassal and Boleslaw the ruler. Probably these factors influenced Bolesław III's decision of a terrible punishment to Zbigniew: a year later, in 1112, he was blinded on Bolesław III’s orders.
Bolesław III was excommunicated by Archbishop Martin I, whom remained as strong a supporter of Zbigniew as ever. The crime committed against Zbigniew launched a political crisis in the Piast monarchy, and caused public outrage. The sources don't provide information on whether Bolesław III was indedd excluded from the community of the Church.
Bolesław III then probably decided to make a public penance as a result of the negative public response to Zbigniew's blinding. His aim was to rebuild his weakened authority and gain the favor of the supporters of his brother. According to Gallus Anonymous, Bolesław III after his repentance, asked and received Zbigniew's forgiveness.
Little is known of the death of Zbigniew. K. Jasiński in the pages of his publication Rodowód pierwszych Piastów advocated an immediate death after the blinding, like S. Kętrzyński, but didn't exclude the opposite view. J. Bieniak assumed, however, that Zbigniew's death came after 1114. An interesting reference contained in an obituary from the Benedictine monastery in Lubin recorded the death on 8 July 1113 of a monk from Tyniec Abbey called "Brother Zbigniew". This obituary helped historians to reach a hypothesis that this is Bolesław III's brother. The place of burial is recorded as the Benedictine monastery of Tyniec.
|Ancestors of Zbigniew of Poland|
- Gieysztor, Aleksander (1979). History of Poland. Warsaw: PWN—Polish Scientific Publishers. ISBN 83-01-00392-8.
- "Zbigniew". Internetowa encyklopedia PWN (in Polish). Wydawnictwo Naukowe PWN. Retrieved 2008-01-17.
- "Zbigniew". WIEM Encyklopedia (in Polish). Retrieved 2008-01-17.
- According to A. Brücknera, filologist, slavist, historian of literature and art culture. O. Balzer: Genealogia Piastów, p. 114.
- Some sources gives date of birth after 1070 (WIEM Encyklopedia) and date of death 1112 (Gieysztor 1979, p. 138, 668).
- M. Spórna, P. Wierzbicki: Słownik władców Polski i pretendentów do tronu polskiego, p. 501; B. Snoch: Protoplasta książąt śląskich, Katowice, 1985, p. 13, ISBN 83-216-0644-X.
- According to J. Wagilewicza, Zbigniew's mother was named Krystyna; O. Balzer: Genealogia Piastów, p. 107. Today it is widely accepted that the mother of Zbigniew was Przecława, a member of the Prawdzic family. See A. Nawrot: Encyklopedia Historia, Kraków 2007, p. 738. ISBN 978-83-7327-782-3.
- M. Spórna, P. Wierzbicki: Słownik władców Polski i pretendentów do tronu polskiego, p. 499.
- O. Balzer: Genealogia Piastów, p. 107, doesn't consider Zbigniew's mother as Władysław I's wife; while T. Grudziński believed that until 1080, Władysław I remained unmarried. Other historians assert that Zbigniew's mother was the first wife of Władysław I. K. Jasiński: Rodowód pierwszych Piastów. Poznań, 2004, p. 164. ISBN 83-7063-409-5.
- J. Żylińska: Piastówny i żony Piastów, Warsaw 1975, p. 91.
- Many historians regarded Zbigniew's mother as the first wife of Władysław I. K. Jasiński: Rodowód pierwszych Piastów, p. 164.
- K. Jasiński: Rodowód pierwszych Piastów, p. 182.
- R. Grodecki claimed that this claims had a political origin, and were spread by the Palatine Sieciech and Judith Maria. R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol. I, p. 130.
- S. Trawkowski: Zbigniew [in]: Poczet królów i książąt polskich, Warsaw 1978, p. 72.
- According to Wincenty Kadłubek on 11 April 1079 Bolesław II killed Bishop Stanislaus of Kraków. For several months the Prince struggled with the growing opposition. In the end he had to go into exile. A. Gieysztor: Bolesław II Szczodry [in:] A. Garlicki (ed.): Poczet królów i książąt polskich, pp. 59–61.
- M.K. Barański pointed that Władysław I could be only governor of Masovia instead of a independent ruler. M.K. Barański: Dynastia Piastów w Polsce, pp. 173–174.
- M.K. Barański: Dynastia Piastów w Polsce, p. 172.
- R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol. I, p. 130.
- She probably took the veil later and died about 1092.Krystyna Przecława Prawdzic
- O. Balzer concluded that Vratislaus II's coronation took place on 15 June 1086, following the reports of Cosmas of Prague. O. Balzer: Genealogia Piastów, p. 108. W. Mischke, like many other medievalists, pointed that the coronation of Vratislaus II was on 15 June 1085. W. Mischke: Polska korona królów czeskich (in Polish) [retrieved 30 July 2014], p. 11-12, 27-29.
- The reports of Cosmas of Prague about the coronation of Vratislaus II as King of Poland are disputed by many historians. Medievalists consider this a mistake of the chronicler. See G. Labuda: Korona i infuła. Od monarchii do poliarchii, p. 13. A detailed argument who favored Vratislaus II's coronation is presented by W. Mischke. See W. Mischke: Polska korona królów czeskich (in Polish) [retrieved 30 July 2014], pp. 11-29. M. Spórna and P. Wierzbicki believes that the reports of Cosmas are authentic. The title of King of Poland was probably received from the Emperor, who claimed feudal sovereignty over this country. M. Spórna, P. Wierzbicki: Słownik władców Polski i pretendentów do tronu polskiego, p. 496.
- R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol I. pp. 127-128.
- This arrangement was designed to keep the status quo. M. Spórna, P. Wierzbicki: Słownik władców Polski i pretendentów do tronu polskiego, p. 353.
- M. K. Barański: Dynastia Piastów w Polsce, p. 178.
- M. K. Barański: Dynastia Piastów w Polsce, p. 175.
- O. Balzer and K. Jasiński advocated for 1086 as Bolesław's year of birth. O. Balzer: Genealogia Piastów, p. 119; K. Jasiński: Rodowód pierwszych Piastów, pp. 185-187.
- K. Maleczyński, Bolesław III Krzywousty pp 22-23.
- S. Trawkowski: Władysław I Herman [in]: Poczet królów i książąt polskich, Warsaw 1978, p. 67.
- M. K. Barański: Dynastia Piastów w Polsce, p. 275.
- S. Trawkowski: Władysław I Herman [in:] A. Garlicki (ed.): Poczet królów i książąt polskich, p. 67. The Encyklopedia Historia provides the information that Zbigniew was ordained only after ended his studies in Kraków. A. Nawrot (ed.): Encyklopedia Historia, p. 738.
- M. Spórna, P. Wierzbicki: Słownik władców Polski i pretendentów do tronu polskiego, p. 229.
- O. Blazer placed the marriage in 1088. O. Balzer: Genealogia Piastów, p. 115.
- M. Spórna, P. Wierzbicki: Słownik władców Polski i pretendentów do tronu polskiego, p. 353.
- According to medievalists, Zbigniew was incarcelated in Quedlinburg and never accepted the ordination. M. K. Barański: Dynastia Piastów w Polsce, p. 180.
- P. Ksyk-Gąsiorowska: Zbigniew [in]: Piastowie. Leksykon biograficzny Kraków 1999, p. 72. ISBN 83-08-02829-2.
- R. Grodecki believes that the Count Palatine Sieciech, supporter of Władysław I, and Judith Maria were responsible for Zbigniew's placement at the Abbey. R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol I, p. 129.
- The opposition, who supported the rights of Mieszko Bolesławowic and Zbigniew, demanded the legal recognition of the two princes as pretenders to the throne. S. Szczur: Historia Polski – średniowiecze, p. 117.
- R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol. I, p. 128.
- K. Maleczyński: Bolesław III Krzywousty, p. 30.
- Sieciech aimed to rapidly integrate Pomerania into Poland. S. Szczur: Historia Polski – średniowiecze, pp. 117-118.
- M. Spórna, P. Wierzbicki: Słownik władców Polski i pretendentów do tronu polskiego, p. 445.
- K. Maleczyński: Bolesław III Krzywousty, p. 26.
- R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol. I, p. 129.
- In Zbigniew's return was also involved Bretislaus II of Bohemia. M. K. Barański: Dynastia Piastów w Polsce, pp 182-183.
- Zbigniew at first had no impact on the Silesian opposition politics. M. K. Barański: Dynastia Piastów w Polsce, p. 182.
- M. K. Barański: Dynastia Piastów w Polsce, p. 183.
- This date was placed by Jan Długosz in his Chronicles. However, Jan Powierski refuted this and placed the release and consecration of Gniezno Cathedral on 1 May 1099. J. Powierski: Data konsekracji katedry gnieźnieńskiej (1 maja 1099) na tle sytuacji politycznej Polski, Rusi i krajów sąsiednich, "Roczniki historyczne", p. 67 and seq., 1994.
- L. Korczak: Władysław I Herman [in]: Piastowie. Leksykon biograficzny, Kraków 1999, p. 65. ISBN 83-08-02829-2.
- R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol. I, p. 131.
- The decision to give lands to Zbigniew and Bolesław was first mooted in 1093. K. Maleczyński: Bolesław III Krzywousty, pp. 34-35.
- Historians have presented different views about the division of the country. R. Grodecki suggests a first division was made during the reign of Duke Władysław I, in the years 1097-1098, and a second took place after his death in 1102, under the arbitration of Archbishop Martin. R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol. I, pp. 131-135. G. Labuda suggests the division occurred around 1097, but only when Bolesław had completed 12 years of service. G. Labuda: Korona i infuła. Od monarchii do poliarchii, Kraków 1996, pp. 16-69. ISBN 83-03-03659-9. K. Maleczyński sets the date of the first division at 1099. J. Wyrozumski: Historia Polski do roku 1505, Warsaw 1984, p. 101. ISBN 83-01-03732-6.
- For the inclusion of Sandomierz and Lublin as part of Bolesław's domains advocated K. Maleczyński. K. Maleczyński: Bolesław III Krzywousty, p. 40.
- K. Maleczyński: Bolesław III Krzywousty, p. 41.
- S. Szczur: Historia Polski – średniowiecze, p. 119.
- Zbigniew would inherit the lands of Władysław I which were critical to the integrity of Poland as a sovereign state. R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol. I, pp. 131-132.
- S. Szczur: Historia Polski – średniowiecze, p. 120.
- Zdzisław S. Pietras, Bolesław Krzywousty, Cieszyn 1978, pp. 45-60.
- P. Jasienica: Polska Piastów, Warsaw 2007, p. 116. ISBN 978-83-7469-479-7.
- M. K. Barański: Dynastia Piastów w Polsce, p. 185.
- Z. S. Pietras: Bolesław Krzywousty Cieszyn 1978, p. 58.
- P. Jasienica: Polska Piastów, Warsaw 2007, p. 117. ISBN 978-83-7469-479-7.
- Zbigniew counted with the support of the high Church hierarchy and noble families Prawdzic and Turzym, while on Bolesław's side are the families Awdawiec, Jastrzębiec, Strzemieńczyk and Łabędź. K. Maleczyński: Bolesław III Krzywousty, pp. 53-56.
- K. Maleczyński pointed that Bolesław also received Sieradz and Łęczyca. K. Maleczyński: Bolesław III Krzywousty, pp 50-51.
- S. Szczur: Historia Polski – średniowiecze, p. 121.
- T. Manteuffel believed that Zbigniew tried to play the role of tutor of his younger half-brother. See T. Manteuffel: Polska wśród nowych państw Europy [in:] T. Manteuffel (ed.), Polska pierwszych Piastów. Państwo, społeczeństwo, kultura., p. 34.
- R. Grodecki argues that Zbigniew established the Principle of the Seniorate and that he was supported by Polish society; The equality of both rulers came only in 1106. R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol. I, pp. 135-136. G. Labuda disputes this, and pointed out that Zbigniew maintained the equality of rule between both districts since the division of 1102.. G. Labuda: Korona i infuła. Od monarchii do poliarchii, Kraków 1996, pp. 16-17, ISBN 83-03-03659-9.
- R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol. I, p. 135.
- M. K. Barański: Dynastia Piastów w Polsce, p. 189.
- M. K. Barański: Dynastia Piastów w Polsce, p. 194.
- M. K. Barański: Dynastia Piastów w Polsce, p. 195.
- R. Drogi, Państwo Czeskie Przemyślidów (historia Czech, vol. III, cap. 1) [Access 10 November 2005].
- M. Spórna, P. Wierzbicki: Słownik władców Polski i pretendentów do tronu polskiego, p. 62.
- K. Maleczyński: Bolesław III Krzywousty, pp. 59-60.
- M. K. Barański: Dynastia Piastów w Polsce, pp. 198-199.
- M. K. Barański: Dynastia Piastów w Polsce, p. 199.
- R. Grodecki, S. Zachorowski, J. Dąbrowski: Dzieje Polski średniowiecznej, vol. I, p. 137.
- M. Spórna, P. Wierzbicki: Słownik władców Polski i pretendentów do tronu polskiego, p. 500.
- S. Szczur: Historia Polski – średniowiecze, p. 122.
- K. Maleczyński: Bolesław III Krzywousty, p. 65.
- K. Maleczyński: Bolesław III Krzywousty, p. 68.
- M. K. Barański: Dynastia Piastów w Polsce, p. 201.
- M. Spórna, P. Wierzbicki: Słownik władców Polski i pretendentów do tronu polskiego, p. 63.
- K. Olejnik: Cedynia, Niemcza, Głogów, Krzyszków, Kraków 1988. ISBN 83-03-02038-2.
- "S. Orgelbranda Encyklopedia Powszechna", Warsaw 1902, vol. XII, page 406
- M. Kaczmarek, "Bitwa na Psim Polu", in: Encyklopedia Wrocławia, Wrocław 2000
- M. K. Barański: Dynastia Piastów w Polsce, p. 207.
- Tomasz Ga̜sowski, Jerzy Ronikier, Zdzisław Zblewski: Bitwy polskie. Leksykon, Editorial Znak, 1999.
- P. Ksyk-Gąsiorowska: Zbigniew, [in:] Piastowie. Leksykon biograficzny, Kraków 1999, p. 75. ISBN 83-08-02829-2.
- Z. Dalewski: Rytuał i polityka. Opowieść Galla Anonima o konflikcie Bolesława Krzywoustego ze Zbigniewem, p. 25.
- Z. Dalewski: Rytuał i polityka. Opowieść Galla Anonima o konflikcie Bolesława Krzywoustego ze Zbigniewem, pp. 39-40.
- Z. Dalewski: Rytuał i polityka. Opowieść Galla Anonima o konflikcie Bolesława Krzywoustego ze Zbigniewem, p. 13, 46.
- Z. Dalewski: Rytuał i polityka. Opowieść Galla Anonima o konflikcie Bolesława Krzywoustego ze Zbigniewem, p. 38.
- The date of Zbigniew's blinding is disputed. Cosmas of Prague favored the year 1110 (Kosmasa Kronika Czechów, vol. III, cap. XXXIV. p. 115); for the year 1111 are in favor L. Giesebrecht: Wendische Geschichte aus den Jahren 780-1182, p. 176 and M. Gumblowicz: Zur Geschichte Polens im Mittelalter. Zwei kritische Untersuchunden über die Chronik Baldwin Gallus. Aus dem Nachlass des Verfassers herausgegeben, p. 94; for the year 1112 are in favor O. Balzer: , p. 117, S. Szczur: Historia Polski – średniowiecze, p. 124 and T. Tyc: Zbigniew i Bolesław [in:] Arcybiskup Marcin i Gniezno, p. 23; for a time between 1112-1113 are in favor R. Grodecki, [in:] Gallus Anonymous: Kronika polska, pp. 28-29, M. Plezia, [in:] Gallus Anonymous: Kronika polska, p. 38; and for the year 1113 is in favor K. Maleczyński: Bolesław III Krzywousty, pp. 70-75.
- T. Tyc: Zbigniew i Bolesław [in]: Arcybiskup Marcin i Gniezno, Poznań 1927, pp. 30-40.
- Z. Dalewski: Rytuał i polityka. Opowieść Galla Anonima o konflikcie Bolesława Krzywoustego ze Zbigniewem, p. 144.
- Z. Dalewski: Rytuał i polityka. Opowieść Galla Anonima o konflikcie Bolesława Krzywoustego ze Zbigniewem, p. 145; K. Maleczyński: Bolesław III Krzywousty, pp. 76-77.
- Gall Anonymous: Kronika polska, Wrocław: 2003, p. 159. ISBN 83-04-04610-5.
- K. Jasiński: Rodowód pierwszych Piastów, p. 183.
Zbigniew of Poland
Piast DynastyBorn: ca. 1073 Died: 8 June? 1113?
Władysław I Herman
|Duke of Poland
with Bolesław III
| Succeeded by|
Bolesław III Wrymouth