Harington was born on 26 December 1986 in Acton, London, to Deborah Jane (Catesby), a former playwright, and Sir David Robert Harington, 15th Baronet, a businessman. His full name is Christopher Catesby Harington; his mother named him after Christopher Marlowe, whose first name was shortened to Kit, a name Harington prefers. He did not learn what his full name was until he was eleven years old. Harington's uncle was Sir Nicholas John Harington, 14th Baronet, and his patrilineal great-grandfather was Sir Richard Harington, 12th Baronet. The Haringtons are an ancient family that once spelled their name Haverington and derived the name from their estate, a lordship in Cumberland. The first person identified with their name was one Robert De Haverington, the son of Osulphus or Oswulf whose manor was Flemingby. Through his paternal grandmother, Lavender Cecilia Denny, Harington's eighth-great-grandfather was Charles II of England. Also, through his father, Harington descends from Scottish politician Henry Dundas, 1st Viscount Melville.