Isaac was born to Robert and Elizabeth Hamilton in Bathgate, Scotland one of eight siblings. Little is known of his early life but he is recorded as serving with the 1st Battalion in September 1933 where he received 56 days detention and stoppage of pay as a result of a court martial in the category of "Loss of Public Property, Equipment, etc". He went on to serve 23 days of this sentence at Aldershot Military Prison after which it is presumed that he was transferred to the 2nd Battalion and later to Hong Kong.

Issac is recorded as being wounded on the 11th December 1941 during the defence of Hong Kong and being captured on the 25th when the Garrison surrendered. He was then detained at Sham Shui Po POW camp before embarking onto the Lisbon Maru for movement to the Japanese mainland.

Sadly Issac did not survive the sinking of the Lisbon Maru and he is recorded on column 12 of the Sai Wan Memorial in Hong Kong. He is also remembered in a booklet called West Lothian Men on the Lisbon Maru by Meg Stenhouse who is a resident of West Lothian.

Issac's four medals were issued to his Father on 20th March 1950.

Elizabeth Hartley writes: "I was born in 56, but grew up knowing the story of the uncle who died in the war, in a Japanese POW ship. It affected my dad a lot, he would have been just 18 in 1942 when his older brother died".