Owing to the Allied withdrawal, the vast majority of their dead had to be left on the battlefield. Here they were buried in simple field graves (some little more than their own slit trenches) or in small mass graves dug by the Germans. Kate Ter Horst, whose house was used as a first aid post during the battle, found the graves of 57 men in her garden when she returned after the war. After Arnhem was liberated in April 1945, Grave Registration Units of the British 2nd Army moved into the area and began to locate the Allied dead. A small field north of Oosterbeek was offered on perpetual loan by the Netherlands government to the Imperial War Graves Commission (now Commonwealth War Graves Commission) in June 1945 and the dead were reburied there. Many of those killed during Arnhem's liberation were also buried at the same site. The cemetery was completed in February 1946, originally with the graves marked by metal crosses, although these were replaced by headstones in 1952. Most of the German dead were buried in the "SS Heroes Cemetery" near Arnhem after the battle, but reburied in Ysselsteyn German war cemetery after the war.