From the beginning of the article:
Fifteenth-century Sweden was part of the so-called union of Kalmar, where Sweden, Denmark, and Norway were formally united and ruled by a Danish monarch. Swedish dissatisfaction with the Danish rule made itself known throughout the period. The centralising policies of the Danish rulers threatened the political position of the Swedish aristocracy, and the monarchs also came into conflict with the Swedish clergy, as for instance in matters such as the appointing of bishops. In the 1430s, the dissatisfaction manifested itself in popular revolt against the Danish king as well, and from mid-century the Swedish reign was virtually self-governing. The legacy of the union was nevertheless a strong force in Scandinavian politics throughout the century and well beyond, and the Danish kings continuously tried to renew the union. After the decisive battle of Brunkeberg in 1471, the Swedish self-government, however, had constituted itself for the rest of the fifteenth century. Sweden was virtually an aristocratic republic, ruled by the Council of the Realm, where the Regent of the Realm (‘Riksföreståndaren’) and the Archbishop of Uppsala were the most prominent members.