King Frederick was an adherent of the doctrines of Luther, which had now been commonly accepted in Northern Germany, and from thence were introduced into Denmark. He compelled the Danish bishops to acknowledge him as the head of the Church instead of the Pope, and took possession of a number of cloisters, which he either kept for himself or gave to the nobles. In Norway, too, he gave away some of the cloisters, which, of course, caused great dissatisfaction among the clergy. The discontent in Norway took a very definite form, when, contrary to the Recess, the king sent his son Christian to Norway to be proclaimed heir to the throne. Archbishop Olaf Engelbrektson and a majority of the Council of State then declared that this could not be done, inasmuch as Norway was an elective kingdom; and here the king was obliged to let the matter rest. Meanwhile, the exiled King Christian, encouraged by messages from Norway and Sweden, thought he saw a chance to regain his lost throne. With the aid of Charles V., and some private parties, he gathered an army and a fleet in Holland, and sailed for Norway in October, 1531, with twenty-five ships and 7,000 men. On the way he suffered by great storms and lost ten of his ships, but landed in Norway with the remnants of his fleet. He gained a large number of adherents, and, proceeding to Oslo, laid siege to the fortress of Akershus. Mogens Gyldenstierne, however, defended it well, and when, in the spring (1532), reinforcements arrived, in the form of a strong army of Danes and Lubeckers, Christian made an agreement with Mogens, by which he was to proceed, under a safe conduct, to Copenhagen, in order to personally conduct peace negotiations with his uncle. Upon his arrival in Denmark, however, the agreement was shamefully broken, and the unfortunate king was thrown into prison at Sonderborg. He was placed in a cell having a small barred window high up; the entrance was closed with masonry, and the food was sent in through a hole in the wall. Here he remained for eighteen years. In 1550 he was transferred, by Frederick's successor, to a milder prison in Kallundborg Castle, where he remained until he died, in the beginning of 1559, seventy-eight years old. The Norwegians were severely punished for their alliance with Christian. The chieftains of the Danish party, Bishop Olaf in Bergen and the Danish noblemen, Eske Bilde, Vincentz Lunge and Nils Lykke, held a meeting in Bergen shortly after Christian's defeat and levied a heavy tax on the whole country. The archbishop was fined 15,000 Danish marks. The Norwegians were compelled to relinquish any right, through the Council of State, to elect any other king than the one elected for Denmark.