Prussia, Royal (Polish province)

The feeble-minded Albert Frederick, Duke of Prussia, had had no surviving male heirs; therefore, the Treatise of Warsaw in 1611 had allowed his son-in-law, Elector John Sigismund of the Hohenzollern branch in Brandenburg, to become the duke's legal successor.

The Thirty Years' War had broken out in 1618 and Albert Frederick died, with the duchy passing to John Sigismund, who himself died the following year.

John Sigismund's son, George William, is successfully invested with the duchy in 1623 by the king of Poland, Sigismund III Vasa, thus the personal union Brandenburg-Prussia is confirmed.

Many of the Prussian Junkers (the landed nobility of Prussia and eastern Germany) are opposed to rule by the House of Hohenzollern of Berlin and appeals to Sigismund III Vasa for redress, or even incorporation of Ducal Prussia into the Polish kingdom, although without success.

Because Brandenburg is a fief of the Holy Roman Empire and Ducal Prussia is a Polish fief, a cross-border real union is legally impossible.

However, De facto Brandenburg and Ducal Prussia are to be increasingly ruled as one, and colloquially referred to as Brandenburg-Prussia.

Frederick William, Elector of Brandenburg, reconfirms the nobility's freedom from taxation and its unlimited control over the peasants.

...Thorn (Torun) and ...

...Elbing (Elblag) had not participated in the treaty, with Thorn and Elbing surrendering to Sweden.

A manifesto is issued on November 20, in Opole (Oppeln), calling for public resistance and the return of John II Casimir.

A Polish peasant force in December takes Nowy Sącz.

The partisan Tyszowce Confederation is constituted on December 29 under the auspices of Great Crown Hetman Stanisław Rewera Potocki and Field Crown Hetman Stanisław Lanckoroński in Tyszowce, east of Zamość.

It is the turning point of the war.

The Polish Catholic army, offended by the Swedish siege of Jasna Góra monastery, proclaims a national uprising against the Swedes.

Frederick William I, Elector of Brandenburg and Duke of Prussia, takes the Duchy of Prussia, formerly a Polish fief, as a fief from Charles X Gustav under the terms of the Treaty of Königsberg on January 17, 1656.

The Brandenburgian garrisons in Royal Prussia are withdrawn.

Both Charles X of Sweden and Frederick William, Elector of Brandenburg, agree to establish an alliance against Poland under the terms of the Treaty of Königsberg, signed in Königsberg (Królewiec) on January 17, 1656.

Charles is responsible for forcing the prince-elector to become his ally and vassal.

John II Casimir returns from exile on January 1, 1656.

Stefan Czarniecki joins him later in the month.