greenstone and jadeite traded goods appear in burials. The large pyramid B-1 reaches its final form. Stelas with inscriptions are raised, altars are carved and, as in other sites in the region, objects from Teotihuacan are also found. The latter half of the 6th century is marked by a hiatus in inscriptions and the focus of construction moving to Group A. In the early 7th century, the site seems to have recovered and carved stela reappear with features from the Late Classic. By the latter part of this century, the city has reached its peak period. New and old buildings are faced with limestone and a ballcourt is built. Higher occupational levels are mirrored by the large amount of monuments raised. Fine goods - pyrite mirrors, flint projectile points and jadeite beads - are found in burials. By the 9th century, when other sites are also entering the Terminal Classic, the quality of construction and goods begins to decline. By the 8th and 9th centuries AD, the population at Altar de Sacrificios was falling away. During the last phase of occupation (ca. 900-950 CE), fine paste ceramics portraying people with a different appearance replace previous styles. The evidence suggests that during the Terminal Classic the site was occupied by foreigners and prospered at a time when nearby Seibal was also experiencing a resurgence in its fortunes, in both cases linked to the collapse of the Petexbatún kingdom based at Dos Pilas. It has been suggested that the arrival of outsiders as this time was due to Chontal Maya dominance of the Usumacinta riverine trade route at this time. However, with the collapse of the major cities in the Usumacinta drainage, river trade declined drastically and was unable to be renewed by the newcomers. Altar de Sacrificios, together with the few other surviving polities in the western Petén, declined into stagnating inwardly-focused polities in spite of their longer distance contacts. By the Terminal Classic bone analysis has revealed that the health of the general population was suffering, with increased child mortality, decreased stature and the proliferation of disease, although the elite remained healthy. At the same time the reduced population withdrew into defensible locations at the site. There is little evidence of any occupation after ca. 950 AD. Rulers At least ten rulers are recorded on the monuments of Altar de Sacrificios, and there were probably more. Three rulers governed in