After the assassination of Francisco Pizarro, in retaliation for his father's execution in 1538, Diego de Almagro II, El Mozo, continued to press claims as the rightful ruler of Peru and as leader of his father's supporters. His claims were largely unsuccessful, however, as Pizarro was succeeded as governor by Cristóbal Vaca de Castro, despite claims from his brother Gonzalo Pizarro, whose claims to join arms against the Almagristas and "El Mozo" largely remained unanswered.