 During the reign of his uncle Itzcoatl, Tlacaelel was given the office of Tlacochcalcatl, but during the war against the Tepanecs in the late 1420s, he was promoted to first adviser to the ruler, a position called "Cihuacoatl" in Nahuatl, an office that Tlacaelel held during the reigns of four consecutive "Tlatoque", until his death in 1487.Tlacaelel recast or strengthened the concept of the Aztecs as a chosen people, elevated the tribal god/hero Huitzilopochtli to top of the pantheon of gods, and increased militarism.In tandem with this, Tlacaelel is said to have increased the level and prevalence of human sacrifice, particularly during a period of natural disasters that started in 1446 (according to Diego Durán).