The first unit of the new division to see major combat was the 1st Battalion, 7th Cavalry Regiment, 1st Cavalry Division, led by Lieutenant Colonel Harold G. Moore. The 7th Cavalry was the same regiment that Custer had commanded at the ill-fated Battle of the Little Bighorn. On November 14, 1965, Moore led his troops in the first large unit engagement of the Vietnam War, which took place near the Chu Pong massif near the Vietnam-Cambodia border. It is known today as the Battle of Ia Drang Valley, and is considered to be the first large scale helicopter air assault.