Carvajal later used these funds to journey to Mexico as an aide to its first Spanish viceroy, Antonio de Mendoza. In 1535, he was dispatched to Peru to the relief of newly founded Lima, then under siege by an Inca army. Carvajal led reinforcements to Governor Francisco Pizarro and thereafter played a key role in reestablishing Pizarro's rule against the rival faction of conquistadors led by Almagro the Younger. He continued to lead his cavalry from the front ranks despite his age and obesity and became something of a local legend for his composure in battle. At Chupas, seeing the Imperial Spanish infantry giving way before a hail of fire from Almagro's massed cannons and harquebusiers, Carvajal is said to have ridden to the front of the line and, casting his helmet and cuirass to the ground, exclaimed,