Battle of Las Salinas The Battle of Las Salinas was a military conflict and decisive confrontation between the forces of Hernando and Gonzalo Pizarro against those of rival conquistador Diego de Almagro , on April 26 , 1538 , during the Conquest of Peru . Both camps claimed to represent the authority of the Spanish Crown ; Pizarro ' s forces controlled the province of " Nueva Castilla , " and those of Almagro , " Nueva Toledo . " After an hour of carnage , the battle yielded a victory for Pizarro ' s forces : with Almagro captured and his lieutenant , Rodrigo Orgóñez killed on the field of battle , the Pizarros routed the enemy and took possession of Cuzco . Almagro was executed in July 1538 . Background . The conflict between the Pizarro brothers and Almagro originated in a dispute over the possession of the city of Cuzco during the initial Spanish partition and administration of Peru . While Almagro controlled the city from 1537 , both considered it under their jurisdiction . Almagro ' s enterprise had won him several earlier battles , but although he succeeded in taking the city by a coup de main , Pizarro ' s forces were by far the stronger in the region , leaving him with few options for its defence . Almagro , his fortunes on the wane , invalided by a debilitating disease , turned to Rodrigo Orgóñez to carry out the campaign . Almagro ' s men made their first mistake by failing to secure the Guaitara pass guarding the approach to Cuzco ; their enemy , braving the mountains , made a crossing and appeared in force along the coast . At a war council in Cuzco , Almagro even considered a new round of negotiations with the Pizarros ; Orgóñez is said to have interrupted : " It is too late ; you have liberated Hernando Pizarro , and nothing remains but to fight him . " Accordingly , Orgóñez marched his 500 men toward the ancient Indian salt mines of Cachipampa , situated about 5 km south of Cuzco . His choice of battlefield has been subject to criticism in that the broken terrain limited the use of his cavalry , which accounted for over half his force . The infantry , furthermore , was short on weapons and many armed themselves only with pikes . A battery of six falconet , on the other hand , gave him a marked advantage over his foes . Pizarro ' s army consisted largely of infantry and numbered about 700 . His cavalry was outmatched by Almagro ' s strong force of seasoned cavaliers , but in addition to veteran conquistadors he could rely on a contingent of Imperial arquebus iers recently arrived from Santo Domingo . These redoubtable troops carried large - calibre firearms newly developed for the bloody fighting in Flanders . The battle . Orgóñez placed his infantry in the centre and a division of cavalry on each wing . Pizarro ' s army mirrored this deployment , with Alonso de Alvarado commanding one corps of cavalry and Hernando Pizarro the other . Gonzalo Pizarro led the battalion of infantry which spearheaded the first attack across the small river separating the two armies . Fire from Orgóñez ' s guns bit into Gonzalo ' s column and threw it into disorder , but the swampy ground prevented Orgóñez ' s cavalry from exploiting this advantage . Meanwhile , Pizarro ' s Imperial troops , gaining the other side , opened a murderous fire of double - headed shot on their enemies . With the infantry locked in combat in the marshes , both Pizarro and Orgóñez brought forth their cavalry . On both sides , the left and right wings of cavalry merged into single columns under Orgóñez on one hand and Pizarro on the other . An epic shock followed as the two bodies met at full gallop , the men variously shouting " " ¡ El Rey y Almagro ! " " or " " ¡ El Rey y Pizarro ! " " Orgóñez , in the thick of the desperate fighting , was shot , unhorsed , and murdered while offering his surrender . His death unhinged the cavalry , which began to fall back in confusion despite its superiority . Almagro ' s infantry , meanwhile , stood no chance against the superior firepower of Pizarro ' s men and , after an hour of brave fighting , began to scatter in the direction of Cuzco . Almagro watched the rout from his litter on a hill : " With an agony not to be described , he had seen his faithful followers , after their hard struggle , borne down by their opponents till , convinced that all was lost , he succeeded in mounting a mule , and rode off for a temporary refuge to the fortress of Cuzco . "