Thus deified, he had the power of opening and shutting every thing in the universe: he was arbiter of peace and war, and keeper of the door of heaven. He was the god who presided over the beginning of all undertakings; the first libations of wine and wheat were offered to him, and the preface of all prayers directed to him. The first month of the year took its denomination from Janus.

It is certain that Janus early obtained divine honors among the Romans. Numa ordained that his temple should be shut in time of peace, and opened in time of war, from which ceremony Janus was called Clusius and Patulcius.

The peculiar offerings to Janus were cakes of new meal and salt, with new wine and frankincense. In the feasts instituted by Numa, the sacrifice was a ram, and the solemnities were performed by men, in the manner of exercises and combats. Then all artificers and tradesmen began their works, and the Roman consuls for the new year solemnly entered on their office: all quarrels were laid aside, mutual presents were made, and the day concluded with joy and festivity. Janus was seated in the centre of twelve altars, in allusion to the twelve months of the year, and had on his hands fingers to the amount of the days in the year. Sometimes his image had four faces, either in regard to the four seasons of the year, or to the four quarters of the world: he held in one hand a key, and in the other a sceptre; the former may denote his opening, as it were, and shutting the world, by the admission and exclusion of light; and the latter his dominion over it.