sentences:  In the Preclassic the population was spread out along the east bank of the river; in the Late Preclassic the population began to concentrate on the ridge, and this continued into the Early Classic period.In the late 4th century AD Río Azul came to be dominated by the city of Tikal.Scenes depicting the sacrifice of at least eight nobles are sculpted on a series of three circular altars dated to AD 385; this has been interpreted as the sacrifice of the local elite after a takeover by Tikal and its Teotihuacano allies.