Complex sentence: His paternal grandparents, Santiago Barbosa and Lorenza Aguilar, were criollos of Cocula; and his maternal grandparents, Ignacio Mendoza and Juliana Montaño, were from San Jacinto.
Split into simpler sentences: His paternal grandparents were Santiago Barbosa and Lorenza Aguilar were criollos of Cocula. His maternal grandparents were Ignacio Mendoza and Juliana Montaño, however, were from nearby San Jacinto.