Brief addressed to Adolf, Count of Nassau, sanctioning his election to the see of Mainz.

In 1459 Diether von Isenburg was elected as Archbishop of Mainz, but soon became seen by Pius II as disobedient. On 21 August 1461, from his summer palace at Tivoli, Pius II, after careful diplomatic negotiations with the emperor and the German imperial electors, announced Diether's deposition, and his replacement by Adolf von Nassau, the unsuccessful candidate of 1459. Adolf proclaimed the papal action in Mainz in late September 1461. Over the next months Fust and Schöffer printed nine different documents relating to this “Cathedral War”, four of which in two editions each, some supporting Adolf and Pius II, and some Diether von Isenburg. Diether, who was supported by most of the citizens of Mainz, did not go easily. Finally, in late October 1462, Adolf used mercenary troops to capture Mainz, and expel temporarily many of its citizens; Mainz was stripped of its status as an Imperial Free City.