In 1397, Denmark entered into a personal union with Norway and Sweden, united under Queen Margaret I. The three countries were to be treated as equals in the union. However, even from the start, Margaret may not have been so idealistic—treating Denmark as the clear "senior" partner of the union. Thus, much of the next 125 years of Scandinavian history revolves around this union, with Sweden breaking off and being re-conquered repeatedly. The issue was for practical purposes resolved on 17 June 1523, as Swedish King Gustav Vasa conquered the city of Stockholm. The Protestant Reformation spread to Scandinavia in the 1530s, and following the Count's Feud civil war, Denmark converted to Lutheranism in 1536. Later that year, Denmark entered into a union with Norway.