The Mbayá or Mbyá are an ethnic group, commonly called "Indians", which formerly ranged on both sides of the Paraguay River, on the north and northwestern Paraguay frontier, eastern Bolivia, and in the adjacent province of Mato Grosso do Sul, Brazil. They have also been called Caduveo. In the 16th century the Mbayá were called Guaycuru, a name later used generically for all the nomadic and semi-nomadic Indians of the Gran Chaco. The Kadiwéu people of Brazil are the surviving branch of the Mbayá.