George Arthur was born in Plymouth, England. He was the youngest son of John Arthur, from a Cornish family, and his wife, Catherine, daughter of Thomas Cornish. He entered the army in 1804 as an ensign and was promoted lieutenant in June 1805. He served during the Napoleonic Wars, including Sir James Craig's expedition to Italy in 1806. In 1807 he went to Egypt, and was severely wounded in the attack upon Rosetta. He recuperated and was promoted to captain under Sir James Kempt in Sicily in 1808, and participated in the Walcheren expedition in 1809.