After his return, De Almagro was surprised to learn of the Inca Manco's rebellion. Diego de Almagro sent an embassy to the Inca, but they mistrusted all of the Spaniards by this time. Hernando Pizarro's men formed an uneasy truce with De Almagro's men, surveying to determine the boundaries of their leaders' royal grants. They needed to determine in which portion the city of Cuzco was located. However, De Almagro's troops quickly took the city and imprisoned the Pizarro brothers, Hernando and Gonzalo, on the night of 8 April 1537.