Curtis or Curtiss is a common given name and surname of English origin derived from the Old French "curteis," which means 'polite, courteous, or well-bred.' It's related with the Spanish and Portuguese surname Cortes. It was brought to England (and subsequently, the rest of the Isles) via the Norman Conquest. This is evidence to suggest the name itself is a phonetic corruption of Curthose, the nickname ascribed to Robert II or also Curtmantle, the surname used by Henry II, the first of England's Plantagenet kings. It could also be a variation of the established medieval surname, Curthoys. Though it is unclear whether "Curtis" and "Curtiss" are directly related, the latter is also considered here for convenience.