William Tasker was born in 1740 at Iddesleigh, Devon.[1] He was the only son of William Tasker (1708–1772) and Jane Vickries (died 1795). His father was rector of Iddesleigh, Devonshire, from 6 July 1738.[2] He was educated at Barnstaple, then attended Exeter College, Oxford, matriculating on 20 February 1758. He remained there as sojourner and obtained a B.A. on 2 February 1762.