The Battle of Aachen was a major combat action of World War II, fought by American and German forces in and around Aachen, Germany, between 2–21 October 1944. The city had been incorporated into the Siegfried Line, the main defensive network on Germany’s western border; the Allies had hoped to capture it quickly and advance into the industrialized Ruhr Basin.

Although most of Aachen’s civilian population was evacuated before the battle began, much of the city was destroyed and both sides suffered heavy losses. It was one of the largest urban battles fought by U.S. forces in World War II, and the first city on German soil to be captured by the Allies. The battle ended with a German surrender, but their tenacious defense significantly disrupted Allied plans for the advance into Germany