In September 1464 the last representing ducal noble of Stettin family - Otto III died. Put in a claim a form of Pomeranian lands - they notified: ruler of Brandenburg, elector Frederick II, duke of Slupsk Eric II, duke of Wolgast - Wartislaw X and his sons. The position of Pomeranian dukes enforced (in face claims of Brandenburg) regulating of relation with Poland, who happened during meeting of Eric II with Casimir IV Jagiellon in Bydgoszcz. Quarrel for the Duchy of Stettin transformed into armed conflict, finished with conclude peace in Przeclaw in May 1472. Contained compromise confirmed superior laws of Brandenburg elector, but concurrently left Duchy of Stettin in role of fiefs, who was under rule Wartislaw X and Eric II. This regularity remained post mortem Eric II in 1474 and to commencement of power by Bogislaw X, who was his son. Bogislaw refused oath of fealty to Brandenburg margrave, and it came up to renewed escalation of this conflict.

During this war died Warcislaw X and as result of his death, an only Pomeranian ruler been Boguslaw X. The Pomeranian Brandenburg conflict ended with defeat of Bogislaw and in progress of the peace in 1479 during confirmation again in Przeclaw, Bogislaw had to take his possessions as a fief from Albrecht elector. In 1486, post mortem Albrecht, Bogislaw refused renewal of fealty. Post mortem his own wife Margaret (daughters of Frederic II), narrowed close ties with Poland marrying in 1491 Anne - the daughter of Casimir IV Jagiellon. As result of this situation, John - new ruler of the Brandenburg March, was decided on make concessions. In the pact contained on 26 of March 1492 in Pyrzyce, Bogislaw (and his successors) they were exempt from a liability of the oath of fealty. In exchange for this Bogislaw promised, that he wasn't would stay a vassal of any other ruler and in case of expiration of the House of Griffins, the Duchy of Pomeranian on basis succession, will enter into possession of the Brandenburg March.

The war thirty-year, begun events in 1618 in Bohemia, embraced with its area of activity, also Middle Pomerania. In 1624 duke of Bogislaw XIV claimed from the city of putting out of the contingent fifteen mounted infantry and one hundred infantrymans. Slupsk soldiers together with contingent of nearby towns; Slawno, Bytow, Darlowo, Szczecinek and Lebork created the campaign, which a challenge was protection of ports and entry points of Middle Pomerania. For heavy costs living of soldiers under arms in town, the company remained partly dispersions, however in summer in 1627, one appointed them again. Soon on the Pomeranian lands entered caesarean army and habitants were fallen by cost-of-living of her maintenance. During stay of the army, Slupsk affected two epidemics also in 1629 town was visited by famine disaster, in consequence of crop failure in the previous year.

After manpower withdrawal of caesarean armies, duchy was occupied in 1630 by Swedish army. For Slupsk town this meant renewed contribution and housing acts. After defeat of Swedish armies under Nördlingen in 1634 financial burdens for the town, still grew up. The sociopolitical situation additionally complicated, expiration in 1637 the House of Griffins. In accord with pre-agreed of the inheritance rules, a rightful successor of Bogislaw XVI, was brandenburgian elector.

Swedes tried to use come into being situation and to locate occupied territory. At first the authority exercised the Pomeranian caretaker government. Later this government became dismissed. Since 1638 in the name of Swedish monarch rule were exercised by general governor - commander of the Swedish army, general Jan Baner. In 1648 became contained the Peace of Westphalia, which finished the Thirty Years' War. In accord with decisions of the treaty, Slupsk together with lands get under rule of Brandenburg.