After they arrived in the New World, the Spanish started several expeditions to Guatemala, beginning in 1519. Before long, Spanish contact resulted in an epidemic that devastated native populations. Hernán Cortés, who had led the Spanish conquest of Mexico, granted a permit to Captains Gonzalo de Alvarado and his brother, Pedro de Alvarado, to conquer this land. Alvarado at first allied himself with the Kaqchikel nation to fight against their traditional rivals the K'iche' (Quiché) nation. Alvarado later turned against the Kaqchikel, and eventually brought the entire region under Spanish domination.