To complete the work of reform and to give the Church in Denmark a new constitution Bugenhagen, a disciple of Luther, was invited to the capital (1539). He began by crowning the king according to Lutheran ritual, and by drawing up a form of ecclesiastical government that placed full spiritual power in the hands of the civil ruler. As in Germany, superintendents were appointed in room of the bishops who had resigned. When the work of drawing up the new ecclesiastical organisation had been finished it was submitted to and approved of by the Diet held at Odensee in 1539. In another Diet held in 1546 the Catholic Church in Denmark was completely overthrown, her possessions were confiscated, her clergy were forbidden to remain in the country under penalty of death, and all lay Catholics were declared incapable of holding any office in the state or of transmitting their property to their Catholic heirs. By those measures Catholicism was suppressed, and victory was secured for the Lutheran party.
Norway, which was united with Denmark at this period, was forced into submission to the new creed by the violence of the Danish kings, aided as they were by the greedy nobles anxious to share in the plunder of the Church. Similarly Iceland, which was subject to Denmark, was separated from Rome, though at first the people offered the strongest resistance to the reformers. The execution, however, of their bishop, John Aresen, the example of Denmark and Norway, and the want of capable religious leaders produced their effects, and in the end Iceland was induced to accept the new religion (1551). For a considerable time Catholicism retained its hold on a large percentage of the people both in Norway and Iceland, but the severe measures taken by the government to ensure the complete extirpation of the Catholic hierarchy and priesthood led almost of necessity to the triumph of Lutherani**.
By the Union of Kalmar (1397) Sweden, Norway, and Denmark were united under the rule of the King of Denmark. The Union did not, however, bring about peace. The people of Sweden disliked the rule of a foreigner, and more than once they rose in rebellion against Denmark.
In the absence of a strong central authority the clergy and nobles became the dominant factors in the state, especially as they took the lead in the national agitations against King Erik and his successors.
As in most other countries at the time, the Church was exceedingly wealthy, the bishoprics and abbacies being endowed very generously, but unfortunately, as elsewhere, the progress of religion was not in proportion to the worldly possessions of its ministers. Endowment had destroyed the liberty of election so essential for good administration, with the result that the bishops and other ecclesiastical dignitaries were selected without much regard for their qualifications as spiritual guides. Yet it must be said that in general the administrators of the ecclesiastical property were not hard task-masters when compared with their lay contemporaries, nor was there anything like a strong popular feeling against the Church. Still the immense wealth of the religious institutions, the prevalence of abuses, and the failure of the clergy to instruct the people in the real doctrines of their faith were a constant source of menace to the Church in Sweden, and left it open to a crushing attack by a leader who knew how to win the masses to his side by proclaiming himself the champion of national independence and of religious reform.
In 1515 Sten Sture, the administrator of Sweden, supported by the Bishop of Linkoping as leader of the popular party, made a gallant attempt to rally his countrymen to shake off the Danish yoke.
Unfortunately for the success of his undertaking he soon found a dangerous opponent in the person of Gustaf Trolle, Archbishop of Upsala, the nominee and supporter of the King of Denmark. The archbishop threw the whole weight of his influence into the scales of Denmark, and partly owing to his opposition, partly owing to the want of sufficient preparation the national uprising was crushed early in 1520. Christian II. was crowned King of Sweden by the Archbishop of Upsala. He signified his elevation to the throne by a general massacre of his opponents which lasted for two days, and during which many of the best blood of Sweden were put to death (Nov. 1520). The archbishop was rewarded for his services to Denmark by receiving an appointment as region or administrator of Sweden. He and his party made loud boast of their political victory, but had they been gifted with a little prudence and zeal they would have found good reason to regret a triumph that had been secured by committing the Church to the support of a Danish tyrant against the wishes of the majority who favoured national independence. Religion and patriotism were brought into serious conflict, and, given only a capable leader who would know how to conduct his campaign with skill, it was not difficult to foresee the results of such a conflict.
As it happened, such a leader was at hand in the person of Gustaf Eriksson, better known as Gustavus Vasa. His father had been put to death in the massacre of Stockholm, and he himself when a youth had been given as a hostage to the King of Denmark. He made his escape and fled to Lubeck, where he was kindly received, and remained until an opportunity arose for his return to Sweden. He placed himself immediately at the head of the party willing to fight against Denmark, called upon his countrymen to rally to his standard, and in a short time succeeded in driving the Danish forces from Sweden. He was proclaimed administrator of his country in 1521, and two years later a national Diet assembled at Strengnas offered him the crown.