On 10 May 1543, the skilled and ambitious man backed by Emperor Charles V was elected Prince-Bishop of Augsburg; on 19 December 1544 he was appointed
Cardinal of the
titulus of
Santa Balbina by
Pope Paul III for settling the dispute with the Emperor upon the concessions he had made to several Lutheran princes of the
Schmalkaldic League at the
Fourth Diet of Speyer. Otto however urged on a military expedition against the revolting nobles, which the Emperor prepared by forging an alliance with the (Lutheran) Duke
Maurice of Saxony, when the Protestants in 1546 sparked the
Schmalkaldic War by a preventive strike against the town of
Füssen, a possession of the Augsburg bishop. Though a loyal supporter of victorious Emperor Charles V, he was dissatisfied with the terms of the
Augsburg Interim. His opposition to the religious peace made him unpopular with Protestants. At his residence, he founded the
University of Dillingen under
Pedro de Soto, now a
lyceum, and the ecclesiastical seminary at
Dillingen (1549–1555). In 1564 he transferred the management of these institutions to the
Jesuits. In 1549–1550 and again in 1555, he took part in the papal elections at Rome. The situation of the bishopric worsened in 1552 when it was devastated by the troops of the former ally Maurice, meanwhile
Saxon Elector. The emperor's younger brother King
Ferdinand I, now in charge and prepared to compromise, concluded the
Peace of Passau with Maurice, which led to the 1555
Peace of Augsburg with the Lutheran princes. Otto's advice was no longer in demand and with the abdication of Charles V the next year, his powerful position finally was lost. He once more went to Rome in 1559 and was there made the head of the
Inquisition and, in 1562,
Cardinal-Bishop of Albano. In 1567 he held a diocesan synod at Dillingen. From 1568 he lived full-time at Rome, where he died. == Cultural references ==