Leslie was born in 1919 in Hackney to Harry and Minnie nee Hille and had three siblings, Cyril, Basil and Pamela. Their parents were born in Minsk and became British citizens in 1911. In 1939 the family were living with Minnie’s father in Tring, Hertfordshire where Harry was working as woollen traveller and salesman. Leslie’s mother predeceased him in 1939.

Leslie enlisted into the RAF at Uxbridge early in 1940 and was appointed as a Class F Reservist. On 21 June 1940 he became engaged to Betty Needleman and they married in September 1940. Leslie was killed one month later.

On 4 October 1940 Leslie was ferrying Hurricane II BD819 from RAF Takoradi in Ghana. The aircraft hit a radio mast on a low run, it crash landed and blew up in Oshogbo, Nigeria. 

An obituary in the Jewish Chronicle described Leslie as a former pupil of the Jewish Secondary School. ‘He possessed a fine and generous personality which never failed to charm those who came in contact with him. He was a good all round athlete and a keen member of the Maccabi Boxing Section’.