<Li> Dwight D. Eisenhower </Li> <Li> (Supreme Allied Commander) </Li> <Li> Bernard Montgomery <Dl> <Dd> 21st Army Group: <Dl> <Dd> Second Army </Dd> <Dd> First Army </Dd> <Dd> Ninth Army </Dd> </Dl> </Dd> </Dl> </Li> <Dl> <Dd> 21st Army Group: <Dl> <Dd> Second Army </Dd> <Dd> First Army </Dd> <Dd> Ninth Army </Dd> </Dl> </Dd> </Dl>

What did the battle of the bulge mark