In Roman religion, Terminus was the god who protected boundary markers; his name was the Latin word for such a marker. Sacrifices were performed to sanctify each boundary stone, and landowners celebrated a festival called the "Terminalia" in Terminus' honor each year on February 23. The Temple of Jupiter Optimus Maximus on the Capitoline Hill was thought to have been built over a shrine to Terminus, and he was occasionally identified as an aspect of Jupiter under the name "Jupiter Terminalis".
Ancient writers believed that the worship of Terminus had been introduced to Rome during the reign of the first king Romulus (traditionally 753–717 BC) or his successor Numa (717–673 BC). Modern scholars have variously seen it as the survival of an early animistic reverence for the power inherent in the boundary marker, or as the Roman development of proto-Indo-European belief in a god concerned with the division of property.
The name of the god Terminus was the Latin word for a boundary stone, and his worship as recorded in the late Republic and Empire centred on this stone, with which the god could be identified.Siculus Flaccus, a writer on land surveying, records the ritual by which the stone was sanctified: the bones, ashes, and blood of a sacrificial victim, along with crops, honeycombs, and wine, were placed into a hole at a point where estates converged, and the stone was driven in on top. On February 23 annually, a festival called the Terminalia was celebrated in Terminus' honor, involving practices which can be regarded as a reflection or "yearly renewal" of this foundational ritual. Neighboring families would garland their respective sides of the marker and make offerings to Terminus at an altar—Ovid identifies these, again, as crops, honeycombs, and wine. The marker itself would be drenched in the blood of a sacrificed lamb or pig. There followed a communal feast and hymns in praise of Terminus.