Isaac was born on 16 February 1917 in Pancras, London to Latvia born father Samuel and London born mother Jeanette nee Jacobson and he had an older sister Nellie. Their father died in 1921 and the census from that year lists Jeanette and the children living at 15 St Mark’s Crescent, N.W.1 where Jeanette ran a boarding house. Nellie married Roger Tisca, a French physician, in 1937 and after the war they lived and died in France.

Isaac attended Northampton Polytechnic and was awarded a B.Sc. in Civil Engineering and in 1939 he was living at Hall Farm, Curdworth in Sutton Coldfield and where he was working as a civil engineer. In December 1939 he attested into the Royal Engineers as a 2nd Lieutenant becoming a Captain at the time of his death.

By 1939, Jeanette was running a boarding house at 6 Eaton Road, Hampstead in London. On 20 December 1941, a violent quarrel took place between two lodgers, Jeannie Marti and her lover Arthur Jennings. It was reported in the newspapers that Isaac Goodfriend, a soldier, son of the landlady, said that when he came in late on Tuesday night he saw there was a light in Jennings room. The light was still on the next evening and he forced the door. The couple were dead in bed. Actress Jeannie had shot Arthur and then killed herself.

On 10 July 1942, another tragic event took place at the boarding house when Jeanette was killed accidently by electrocution aged fifty-three. She was found unconscious clutching a live wire which was used as a wireless aerial.

On 10 May 1943, Isaac was walking with Corporal Lee along the railway track near Market Bosworth. Corporal Lee was instructed by Isaac to return to collect his gas cape. A light engine came along and Lee stepped off the line and when he returned he found Isaac unconscious and he died four hours after admission to Leicester Royal Infirmary. His death certificate states he died from multiple injuries caused by being knocked down by a light engine while walking on the railway in the course of his military duties and was an accidental death.