The Chichimecas came to rule here under Xolotl starting around 1120. The city was refounded by these people and the remaining Toltecs. The population increased with the arrival of the Tlaxcaltecas. In 1324, a king named Quinantzin, reorganized the area politically, making Tulancingo the head of a province. Tulancingo marched against Texcoco, but was defeated. In the early 15th century, this same Texcoco, under Huitzilihuit, conquered Tulancingo, putting it within the Aztec Empire. In 1431, the Tulancingo area was again reorganized politically under Itzcoatl and Nezahualcoyotl.