 They and other Siouan tribes traditionally competed with and were in conflict with the members of the Powhatan Confederacy, Algonquian-speaking tribes who generally inhabited the coastal Tidewater area along the Atlantic and rivers feeding it.They also were subject to raids by Iroquois from the north, who were based south of the Great Lakes in present-day New York and Pennsylvania.By the end of the 17th century, the Monacan had been decimated by warfare and infectious diseases carried by the mostly English colonists and traders; their survivors were absorbed into other Siouan tribes.