Elias Durnford was born in Ringwood, Hampshire, England, on June 13, 1739, the son of Elias Durnford. He joined the British Army's Corps of Engineers (later the Corps of Royal Engineers) in March 1759. After participating in the Siege of Belle Isle (1761) as an ensign and the Siege of Havana (1762) as a lieutenant, he was made an aide-de-camp and later served as chief engineer and surveyor-general of West Florida. Durnford lived in Pensacola and was lieutenant-governor of West Florida from 1769-1781. During the Revolutionary War, he commanded British troops against Spain, including at the siege of Mobile. He returned to England after the British surrender and was initially stationed in Newcastle. He went back to the Americas in the 1790s, when he participated in campaigns in Martinique, Guadeloupe, and St. Lucia. He and his wife, Rebecca Walker, married on August 25, 1769, and had nine children, including Elias Walker Durnford (1774-1850). Elias Durnford died in Tobago on June 21, 1794.
Andrew Durnford (1744-1798), Elias Durnford's brother, joined the Corps of Engineers in 1770 and also served in North America during the Revolutionary War. In 1779, he became an assistant quartermaster-general in West Florida, and from 1783-1796 he was stationed primarily in Bermuda, where he became the first mayor of St. George's. In 1772, he married Jemima Margaret Isaacson. In 1796, he was suspended after accusations of financial malfeasance, and he died on September 10, 1798, while awaiting his court martial.