Since at least 965 the title was held by the Archbishop of Mainz as the most important Archbishop and most noble Prince-Elector of the Holy Roman Empire until the See of Mainz was secularized in 1803. The Archbishop of Mainz was Primus inter pares of the German Prince-electors and chairman of the Council of Electors at the Imperial Diet of the Holy Roman Empire. He was the Pope's legatus natus (substitute) north of the Alps. Also he had the right to convoke and to preside over the Electors' Council to elect a new Emperor.
The honorary title Primas Germaniae also was held by the most noble ecclesiastical member of the Council of the Princes at the Imperial Diet: first the Archbishop of Magdeburg until the see of Magdeburg was secularized in 1648; thereafter the Archbishop of Salzburg.