Brigadier Richard N. Gale, who would later command the 6th Airborne Division, took command of the 1st Parachute Brigade on its formation in September 1941. A triangular brigade formation with three battalions, Gale decided that rather than dividing the 11th Special Air Service Battalion among the brigade's battalions, he would keep the already trained unit together. On 15 September it was renamed the 1st Parachute Battalion, which, together with the newly raised 2nd and 3rd Parachute Battalions, now formed the 1st Parachute Brigade. These battalions were formed from volunteers aged between twenty-two and thirty-two years of age. Only men in infantry units were selected and only ten men from any one unit were allowed to leave. Early in 1942 the brigade was joined by the 4th Parachute Battalion, the 16th (Parachute) Field Ambulance, and the 1st (Parachute) Squadron, Royal Engineers (RE). The 4th Parachute Battalion left the brigade in July to become the first battalion in the 2nd Parachute Brigade.