The Codex Xolotl (also known as Codicé Xolotl) is a postconquest cartographic Aztec codex, thought to have originated before 1542. It is annotated in Nahuatl and details the preconquest history of the Valley of Mexico, and Texcoco in particular, from the arrival of the Chichimeca under the king Xolotl in the year 5 Flint (1224) to the Tepanec War in 1427.