John was the eldest child of Major John Wilberforce Hare and his wife Irene Victoria Eardley-Wilmot who were married in 1918. He was born at Lydd, Kent. He had a twin brother and sister, Charles Colville and Irene born in 1922 and a younger brother Owen F.F born in 1923.

Irene Eardley-Wilmot was a great-granddaughter of Cyrus W Field, the American who had the inspiration for the Atlantic cable.

John was educated at Ampleforth and matriculated in 1937. His BA was awarded in 1941.

He followed his father into the Royal Artillery and was gazetted as a 2nd Lieutenant on 28 December 1939. He was serving in the 80 Anti-tank Regiment when he was killed in Malaya.

He was awarded the Military Cross.

His name is on the Singapore Memorial, Column 3

He is commemorated on the War Memorial at Parish Church of St Mary the Virgin in Burpham, Sussex along with his brother Charles who was killed at El Alamein on 27 October 1942.