Harold was born in Wolverhampton on 23 April 1896, the son of William and Emma Leadbeater. In 1901, he was living with his parents at 4 High Street, Portobello, Wolverhampton, along with his sisters Annie E., Eveline, Sarah A. and Margery. His mother died in 1909, and by 1911 Harold was living alone with his widowed father in Cudworth, Cheshire. Harold was working as an underground winch driver at a coal mine.
In February 1915, Harold enlisted in the 14th Battalion of the York & Lancaster Regiment (number 14/581), by which point he was working as a miner and still living in Cudworth. He served in the Meditteranean and in France until October 1917, before he returned to serve at home. He was discharged on 30 May 1918 due to sickness, and issued with the Silver War Badge (number 436728) on 7 August 1918.
He married Alice Goose in Barnsley on 28 February 1920. Harold’s son, Colin, was born on 5 April 1926, but as his mother’s maiden name was Eden, he does not appear to have been Alice’s son. In 1937 Harold married again, to Margaret Greatorex, also in Barnsley. In 1939, Harold, Margaret and Colin were living in Cudworth, and Harold was working as a colliery haulage hand. He died in Barnsley in 1950.