Born on 1st Jul 1913, he was commissioned into the Regiment of Artillery on 29th Aug 1933. He was the second Indian Officer to be commissioned into the Regiment of Artillery. During World War II, as a Major, he took part in the operations in the Middle East and was awarded the Distinguished Service Order (DSO) for an outstanding action in Libya on 27th May 1942.

General Kumaramangalam took over as General Officer Commanding –in - Chief, Eastern Command in May 1963. In Nov 1964 he was appointed Deputy Chief of the Army Staff and on 15th Jan 1965 he became Vice Chief of the Army Staff. General Kumaramangalam took over as the Chief of the Army Staff on June 8th 1966, the first Indian gunner officer to reach this coveted appointment. The tenure of General Kumaramangalam as Chief of the Army Staff was marked by an unpublicised but exhaustive re-organisation of the service, up gradation of weapons, training and tactics based on the lessons learned from the 1965 war.

General Kumaramangalam was a keen cricketer, horseman, show jumper and an avid polo player. He was a member of the MCC, a Fellow of the Royal Horticultural Society, President of Indian Polo Association and Equestrian Federation of India. He was Senior Colonel Commandant of Regiment of Artillery from 5th Jul 1959 to 4th Jul 1969 and Honorary Colonel Commandant from 5th Jul 1969 to 30th Jun 1975. He passed away on 13th Mar 2000.