 Thomas Fairfax was born on 16 April 1657, the great-grandson of Thomas Fairfax, 1st Lord Fairfax of Cameron of the Scottish peerage, not to be confused with his cousin and Civil War leader Thomas Fairfax, 3rd Lord Fairfax of Cameron.His father was Henry Fairfax, 4th Lord Fairfax of Cameron and his mother was Francis Barwick.Fairfax graduated from Magdalen College, Oxford in 1675 and served in the Yorkshire Militia under the Earl of Danby.