This chapter reviews existing chronologies of Chichen Itza and attempt to resolve some of the inconsistencies among them. The chapter combines different lines of evidence with data from recent stratigraphic excavations of the Great Terrace, employing Bayesian calibration of radiocarbon determinations to generate a more precise chronology for the site. The history of the ancient Maya city of Chichen Itza, Yucatan, Mexico, has been a subject of debate in archaeology, epigraphy, and art history for more than a century. Despite abundant scholarly attention, little agreement has been reached on a coherent chronological framework for the site. Contradicting chronologies based on hieroglyphic inscriptions, ethnohistorical sources, ceramic typologies, architectural styles, and absolute dates have been proposed. Such alternative chronologies reflect past and current interpretations of ancient Maya history. The nature and timing of the transition between the Terminal Classic and Early Postclassic periods are important and controversial issues in the archaeology of the northern Maya lowlands.