 He was the youngest son of Nathaniel Stephens, rector of Alphamstone in Essex, and was born there.He was educated at the free school at Harwich, and at an early age obtained an appointment as clerk in the navy victualling office, as his eldest brother, Tyringham Stephens, had previously done.After his return from his voyage round the world, Rear-admiral George Anson (afterwards Lord Anson) took notice of young Stephens, and had him moved to the admiralty.