The term "brigade" is a basic military organizational institution. During the Vietnam War, a division was organized into three brigades, with each brigade commanded by a colonel. A division consists of about 20,000 people. There were also separate infantry brigades functioning in the Vietnam War. The 11th, 196th, and 198th Infantry Brigades fought in the war until 1967, when they were brought together to reconstitute the Americal Division, or the 23rd Infantry. The 199th Infantry Brigade and the 173rd Airborne Brigade continued to fight as independent entities. A number of combat support brigades, designed to provide supplies, medical care, and maintenance, also functioned in South Vietnam during the 1960s and 1970s.