Around 1450 the Chajoma, led by their king Lajuj No'j, moved to Mixco Viejo (Jilotepeque Viejo) from Ochal to make their capital more inaccessible to their hostile neighbours. In spite of this, Iximche defeated the Chajoma and Jilotepeque Viejo became subject to the Kaqchikel kingdom. Groups C and E show Kaqchikel influence in their architectural styles, while groups A and B have a purer Chajoma architectural style. Both ballcourts appear to have been remodelled after the Kaqchikel fashion, with thick coatings of stucco.
Around the 13th century, Group A underwent a major remodelling, including the construction of a new retaining wall and the infilling of the 12-metre (39 ft) wide area between the old and new walls, creating a much expanded terrace for the construction of the group's architecture. Owing to its possession of two ballcourts, it is possible that Jilotepeque Viejo served as a regional centre for the Mesoamerican ballgame during the Postclassic; no other Postclassic ballcourt has been identified in the area of San Martín Jilotepeque although three of four Classic period ballcourts at other sites appear to have continued in use. Shortly before the Spanish Conquest, the Chajoma under their lord Achi Q'alel rebelled against the Kaqchikels of Iximche.
It is possible that the Chajoma of Mixco Viejo (Jilotepeque Viejo) initially allied themselves with the Spanish together with the Kaqchikel kingdom of Iximche, and that they also rebelled against the Spanish in 1524. It is known that when the lords of Iximche broke their alliance with the conquistadors, they took refuge in Jilotepeque. The site was abandoned after the Spanish conquest and the inhabitants were moved by the Spanish to San Martín Jilotepeque, after which the area was never reoccupied.
