 In 1661, some of the Mbayá migrated east of the river, destroyed a Jesuit mission, also called a reduction, and displaced the Guarani in the old region of Itatin, located southwest of the present day city of Campo Grande, Brazil.The Mbayá and other Guaycuruan groups developed a horse culture, similar in many respects to that of the Plains Indians of North America.They both raided and traded with the Spanish, often making peace with one town or region while attacking another.