Chełmno extermination camp, known to the Germans as the Vernichtungslager Kulmhof, was a Nazi German extermination camp situated 50 kilometres (31 mi) from Łódź, near the Polish village of Chełmno nad Nerem (Kulmhof an der Nehr in German). After the invasion of Poland in 1939 Germany annexed the area as part of the new territory of Reichsgau Wartheland aiming at its complete "Germanization". The camp was set up specifically for that process. It operated from 01941-12-08-0000December 8, 1941 to 01943-04-11-0000April 11, 1943 during Aktion Reinhard (the most deadly phase of the Holocaust), and from 01944-06-23-0000June 23, 1944 to 01945-01-18-0000January 18, 1945 during the Soviet counter-offensive. It was built to exterminate Jews of the Łódź Ghetto and the local Polish inhabitants of Reichsgau Wartheland (Warthegau).