Native American tribes who lived in the area before European colonization included the Nauset, specifically the Manomoy or Monomoy people. The expansive lands over which they roamed were known to them as Manamoyik or Monomoit. Explorer Samuel de Champlain landed here in October 1606 at a place he christened "Port Fortuné", where he contacted (and skirmished with) the Nauset. Twelve years later another group of Europeans gave it the name "Sutcliffe's Inlets". Neither name stuck, and the location was not permanently occupied by Europeans until English settlers reached Monomoit in 1664. The town was incorporated on June 11, 1712, at which point it was renamed after Chatham, Kent, England. Its territory expanded with the annexation of Strong Island and its vicinity on February 7, 1797.