Seine was a department of France encompassing Paris and its immediate suburbs. Its capital was Paris and its official number was 75. The Seine department was abolished in 1968 and its territory divided among four new departments.
From 1929 to its abolition in 1968, the department consisted of the city of Paris and 80 suburban communes surrounding Paris. It had an area of 480 km² (185 sq. miles), 22% of that area being the city of Paris, and 78% being independent suburbs. It was divided into three arrondissements: Paris, Sceaux, and Saint-Denis.
The Seine department was created on March 4, 1790 as the Paris department. In 1795, it was renamed the Seine department after the Seine River flowing through it.
At the first census of the French Republic in 1801, the Seine department had 631,585 inhabitants (87% of them living in the city of Paris, 13% in the suburbs) and was the second most populous department of the vast Napoleonic Empire (behind the Nord department), more populous than even the dense departments of what is now Belgium and the Netherlands. With the growth of Paris and its suburbs over the next 150 years, the population of the Seine department increased tremendously.
By 1968 it contained 5,700,754 residents (45% of them living in the city of Paris, 55% in the suburbs), making it by far the most populous department of France. It was judged that the Seine department was now too large to be governed effectively, and so on January 1, 1968 it was split into four smaller departments: Paris, Hauts-de-Seine, Seine-Saint-Denis, and Val-de-Marne.
The break-up of the Seine department involved the following changes:
- The city (commune) of Paris was turned into a department in its own right, with no other communes inside this department. The official number 75 which was used for the Seine department was given to the new Paris department.
- To the south and southeast of the city, 29 communes of the Seine department were grouped with 18 communes of the Seine-et-Oise department (which was also abolished in 1968) to form the new Val-de-Marne department, and the official number 94 was assigned to this department (a number previously used for the Territoires du Sud territory in the Saharan part of French Algeria).
- To the west of Paris, 27 communes of the Seine department were grouped with nine communes of Seine-et-Oise to form the new Hauts-de-Seine department, and the official number 92 was assigned to this department (a number previously used for the department of Oran in French Algeria).
- Finally, to the north and north-east the 24 remaining communes of the Seine department were grouped with 16 communes of the Seine-et-Oise department to form the new Seine-Saint-Denis department, and the official number 93 was assigned to this department (a number previously used for the department of Constantine in French Algeria).
Taken together, Hauts-de-Seine, Val-de-Marne, and Seine-Saint-Denis, known in France as the petite couronne ("small ring", as opposed to the "large ring" of the more distant suburbs), plus the city of Paris, are larger than the former Seine department (480 km² for the Seine department vs. 762 km² for Paris and petite couronne).
At the 2006 census, the population of the communes that had previously comprised the Seine department was 5,496,468. The population of the department peaked in 1968 at 5,700,754. It then lost inhabitants until 1999 (with a nadir of 5,203,818 inhabitants at the 1999 census) as residents increasingly relocated to the more distant suburbs of the metropolitan area of Paris, but since 1999 it has regained some inhabitants, with a population increase of 292,650 inhabitants between 1999 and 2006. This new population growth after a long period of decline is comparable to what is observed in the central areas of other large Western metropolises such as Inner London.
Of the new departments created in 1968, Paris (75) was the most populous in 2006 with 2,181,371 inhabitants. The Paris department is currently the second-most populous of France behind that of Nord.
The breakup of the Seine department was universally welcomed at the time. However, in the last 40 years large ghettos have appeared in the suburbs of Paris, and Paris itself has become more of a place for the wealthy, with the departure of lower-middle-class residents to the suburbs (banlieues). The building of the large Périphérique freeway around Paris also contributed to the feeling of marked segregation between Paris proper and its suburbs. That has led to some recriminations over the loss of the old Seine department in the sense that it served as a common administration for the city of Paris and its immediate suburbs, creating a sense of community throughout the metropolitan area. In contrast, today rich Paris administers itself solely and leaves the suburbs to their own fate.
However, there are no real plans to revive the old Seine department. Moreover, the creation of the Île-de-France region in the 1970s, which encompasses not only the territory of the former Seine department but also the more distant suburbs of Paris, is the closest thing to a unifying structure for the metropolitan area.