Thomas was born in Melton on 19th November 1887. He was the youngest son of Henry and Elizabeth (née Crane) of Doe’s Alley, Melton, and one of ten children, six daughters and four sons. By 1901, Thomas was the only child left living at home. At this time, he was employed as a telegraph messenger. Three years later, on 16th February 1904, Thomas joined the Royal Navy as a Boy 2nd Class and started training at HMS Ganges on the Shotley Peninsular. The following year, when Thomas reached the age of eighteen, he signed on for a term of twelve years.

When war was declared in 1914, Thomas was serving on HMS Falmouth, a light cruiser that had been commissioned in 1911. His time on the ship came to an end on 22nd March 1915 and, for the rest of that year, he underwent minelaying training and served on coastal patrol ships. On 1st January 1916, he joined the crew of HMS Thetis, a cruiser launched in 1890, that was being used as a minelayer. Thomas left the crew of the Thetis on 4th January 1918 and was posted to Larne in Ireland where he served once more on small, coastal patrol ships.

He was discharged from the Royal Navy on 9th April 1919. For his war service, Thomas received the 1914-15 Star and the British War and Victory Medals.