<human>:  When did the battle of Arnhem take place?
<bot>: The Battle of Arnhem took place in the Netherlands in September 1944. The battle was fought during the Allied invasion of the Netherlands during World War II. The British 1st Airborne Division and the U.S. 82nd and 101st Airborne Divisions were tasked with capturing the bridges over the Rhine River at Arnhem. The 82nd Airborne Division had the most difficult mission, and suffered heavy losses as a result.