This rite was supposed to commemorate the expiation of the murder of his own sister by Marcus Horatius. The young hero with his head veiled had to pass under a beam spanning an alley. The rite was repeated every year on 1 October. The "tigillum" consisted of a beam on two posts. It was kept in good condition at public expenses to the time of Livy. Behind the "tigillum", on opposite sides of the alley, stood the two altars of Janus Curiatius and Juno Sororia. Its location was on the vicus leading to the Carinae, perhaps at the point of the crossing of the pomerium. The rite and myth have been interpreted by Dumezil as a purification and desacralization of the soldiers from the religious pollution contracted in war, and a freeing of the warrior from "furor", wrath, as dangerous in the city as it is necessary on campaign.