Fryderyk Wilhelm

The elector and his fragmented state

Frederick William (1620–1688), later called the Great Elector, inherited Brandenburg and Prussia in 1640 during the Thirty Years' War. His scattered territories had been badly damaged. Ducal Prussia remained a fief of the Polish Crown even though he ruled it personally. That legal position explains his overriding interest in securing sovereignty there during the Deluge¹².

During the Deluge

In 1656 the elector allied with Sweden. The Malbork treaty promised him territory in the Commonwealth in return for military help. His representatives also joined the partition plan agreed at Radnot³⁴.

In 1657 he left the Swedish alliance. In the Wehlau–Bromberg agreements John II Casimir recognised his sovereignty in Ducal Prussia, formerly a fief of the Polish crown. This was a lasting consequence of the war².

His troops had fought with Sweden in the three-day Battle of Warsaw in 1656. Soon afterwards he negotiated a change of alliance. The Treaty of Wehlau in September 1657, confirmed at Bromberg, brought him a major prize that the later Peace of Oliwa did not reverse: the end of Polish feudal suzerainty over Ducal Prussia. It was one of the Deluge's longest-lasting political consequences⁵⁶².

After the war

Frederick William strengthened the army and electoral authority, becoming a major architect of Brandenburg–Prussia's power. His choices show that the conflict in the Commonwealth also reshaped politics around the southern Baltic¹.

Novel and film

Sienkiewicz and Hoffman focus on the Swedish occupation and Kmicic. The elector belongs chiefly to the diplomatic and military background; the film's credited cast does not establish a separate role for him⁷⁸.