The Reformation in Denmark meant the transition from Roman Catholicism to Protestant Lutheranism in the Church of Denmark which was implemented in 1536 at the decision of King Christian III. The Protestant Reformation in Europe did not happen from one day to another though; the transition itself took place in a period of several decades, beginning in the Holy Roman Empire of the German Nation where Martin Luther started it all in 1517. In Denmark, the Reformation required two years of civil war before the new victorious King could come to power and finally carry out the transition.

Prelude

Already in 1525, Hans Tausen, a monk from the monastery of Antvorskov, had begun preaching Lutheran doctrines in Viborg. In the years hereafter, the Lutheran movement began spreading throughout the country, and although King Frederick I had pledged in his håndfæstning ('charter') to fight against Lutheranism, he nevertheless issued an edict to the citizens of Viborg in 1526, obliging them to protect Hans Tausen.

The Lutheran movement had its origins in Germany and was named after Martin Luther who was the prime mover. The movement quickly gained great influence in Denmark, although humanists like Poul Helgesen long tried to maintain a reform movement within the Roman Church instead of abolishing it altogether as the Lutherans would.

During the first years of the 1530s, the King's passivity encouraged the people to attack monasteries and churches. Former King Christian II who had lived in exile since 1526 took advantage of the unrest and issued propaganda writings, agitating for himself and the new Lutheran doctrine. When Frederick I died in 1533, the Council of the Realm could not come to an agreement on who should be the new king. A Roman Catholic majority preferred Frederick's 12-year-old son Hans while a minority supported Hans' half-brother Christian who as duke of Slesvig and Holsten had introduced Lutheranism there during the 1520s.

The election of a new king was postponed for a year due to the disagreement and in the meanwhile the Council of the Realm would rule and the bishops decide what could be preached in their respective dioceses. Moreover, Hans Tausen was accused of heresy and banished from Zealand but the bishop of Roskilde called him back after only one month. Discontent with the nobility taking over control of the country through the Council made citizens from Malmø and Copenhagen along with peasants, especially from northern Jutland, rally around exiled King Christian II.

The Council had furthermore decided to join a Netherlandic-Slesvigian-Holsatian alliance in stead of Lübeck which by Mayor Jürgen Wullenwever had also been represented at the Council's meeting.

Count's Feud

In January 1534, the city government of Malmø led by Mayor Jørgen Kock refused to comply with an order from the archbishopric to expel the Lutheran preachers. Malmø had already for long been a centre of Evangelical activities and responded to the order by occupying Malmø Castle and arresting the overlord. In May, this rebellion was followed up by the German Count Christopher of Oldenburg attacking Holsten. He had been hired by Koch of Malmø and Wullenwever of Lübeck to conquer Denmark, officially i order to restore King Christian II. Count Christopher's participation in the following two years of civil war named it The Count's Feud. The Count's main objective was not Holsten but Zealand where he sailed and he quickly gained control of all Danish territory east of the Great Belt.

On 4 July 1534 representatives of Jutlandic nobility and councillors met in Rye in eastern Jutland. Here the lesser nobility forced the bishops to nominate the Lutheran Christian, Duke of Slesvig and Holsten to the kingship. When the nobility of Funen joined them, Christian agreed and homage was paid to him as King Christian III on 18 August that year in Horsens.

After both Funen and Jutland had rebelled and Sweden and Prussia had become involved in the war in Scania, Lübeck withdrew from the struggle in January 1536, and on 6 April, Malmø surrendered, though without losing neither privileges nor Evangelical doctrine. After the population had starved for months, Copenhagen gave up too and Mayor Ambrosius Bogbinder committed suicide. Like Malmø, Copenhagen did not lose its privileges either and the rebels were granted an amnesty.

The Reformation

Christian III marched into Copenhagen on 6 August 1536 and six days later he carried out a coup. The three bishops who dwelt in Copenhagen were arrested and the rest were tracked down and likewise locked up. The official reason was their hesitation to elect Christian as king and other alleged criminal acts. The real reason was, however, that Christian wanted to kill two birds with one stone: carrying through a Lutheran Reformation and confiscating the bishops' properties, the profits from which was needed to cover the expenses of the recently ended civil war.

The next year, the conditions of the new Evangelical-Lutheran Church was ordered by an ecclesiastical ordinance which was endorsed by Martin Luther himself. It turned against saint worship, fast days, celibacy and everything else that was considered Catholic foolery, and instead it decreed church services to be performed in Danish.

Most monks and nuns by far were allowed to stay in their monasteries (except the greyfriars) and the priests were allowed to keep their churches until they died. Only when the last monk or nun had died was the monastery added to the property of the Crown. Thus, in spite of the fierce procedures followed especially by Bishop Peder Palladius on Zealand, the Reformation became a relatively bloodless affair in Denmark.