The town was devastated in the Thirty Years' War, the Polish–Swedish War and the Great Northern War in the 17th–18th century. In the 17th century it became part of Sweden, in 1720 it was annexed by Prussia, and from 1871 it formed part of the German Empire. In the final stages of World War II, in 1945, the town was heavily destroyed. Since the Oder-Neisse line was made the German-Polish border after the defeat of Nazi Germany in the war in 1945, Gartz is now a border town. After the war it was part of communist East Germany. After the fall of communism in Central Europe and the German reunification, in 1990 Gartz entered a partnership with the nearby Polish town of Gryfino as its twin town, and in 1998 river cruises between the towns were launched. In 1991, the town was assigned to the state of Brandenburg, despite historically belonging to Pomerania. In 1993, a Polish-German school project was established at the local school. The town was affected by the 1997 Central European flood. Many Poles moved to Gartz, and as of 2014, 32 of 62 children in the local kindergarten had non-German parents.