The town changed hands several times; once it was given as payment to soldiers of the Ascanian margraves of Brandenburg. When the last Piast duke Henry XI of Głogów died without issue in 1476, his widow Barbara of Hohenzollern, daughter of Elector Albert Achilles of Brandenburg, inherited the territory of Crossen. The Brandenburg influence met with fierce opposition by Henry's cousin Duke Jan II the Mad of Żagań, who devastated Krosno but in 1482 had to sign an agreement with Albert Achilles, who was able to retain the Krosno area. As a former part of the Duchy of Głogów it officially remained a lien of the Bohemian kingdom until in 1538 King Ferdinand I of Habsburg, renounced all rights to Crossen in 1538, thereby finalizing the district's belonging to the Neumark region of the Brandenburg margraviate.
In 1945 during World War II, the town was conquered by the Soviet Red Army. According to the post-war Potsdam Conference, the town east of the Oder-Neisse line was placed under Polish administration. The German-speaking inhabitants were expelled westward and replaced with Poles. Due to war and expulsion, the population was reduced from 10,800 in 1939 to 2,000 in 1946.