フィンランド公
Crown Prince Gustav Adolf (1594–1632), elder son of Charles IX of Sweden, as heir apparent was made Duke of Finland in 1606, while Östergötland was assigned to his cousin Duke John the younger instead. Gustav Adolf then started to receive ducal revenues from Finland. When he ascended the throne of Sweden in 1611 he readopted "Grand Duke of Finland" among his titles. He was the last to have a real feudal principality of Finland and revenues therefrom.