In Spring 1540, the Caxcanes and their allies struck back, emboldened perhaps by the fact that Governor Francisco Vásquez de Coronado had taken more than 1,600 Spaniards and indigenous allies from the region northward with him on his expedition to what would become the United States’ Southwest.[5] The province was thus bereft of many of its most competent soldiers. The spark that set off the war was apparently the arrest of 18 rebellious indigenous leaders and the hanging of nine of them in mid-1540. Later in the same year the natives rose up to kill, roast, and eat the encomendero Juan de Arze.[6] Spanish authorities also became aware that the natives were participating in "devilish" dances.