Thomas Alexander Brennan was born in Rock Ferry, Cheshire, England on 18 June 1893 and baptised on 20 July that year in St Paul’s Church, Tranmere. He was the son William Brennan, a mariner, and the former Mary Emma Burke and he had one known sibling, his elder brother Charles (b. 1889). 

Brennan’s father apparently died when he was a small child and his mother remarried, becoming Mrs John George Francisco. By 1911 the family home was 61 Percy Street, Bootle where Thomas’ mother ran a boarding house.

Brennan first went to sea in June 1907 at age 14 when he was a boots boy aboard Campania. In April 1912 he was a steward aboard Carpathia when that ship rescued the survivors of the Titanic disaster.

Thomas Brennan remained at sea for the rest of his life, later rising to become chief steward aboard SS Carinthia. In 1923 he married Ida Gertrude Bicknell, née Priestley (b. 31 December 1891 in Ryde, Hampshire), with whom he had two daughters, Peggy and June. 

Thomas Brennan died in Wallasey in April 1966.