DEVOTIO, RITE of. - It was a particular kind of votum in which an individual vowed himself and offered himself in advance to the infernal deities in order to obtain, through his self-sacrifice, the victory of his own side and the defeat of the enemy. Its original meaning is shown by the d. of Decio Mure the elder, at the foot of Vesuvius in 430 B.C.; when victory was in peril, he hurled himself into the mêlée, invoking the gods who protected the fatherland to save the Roman army and to annihilate the opposing one together with him.
The d. differs from the votum in that, in the latter, the human obligation is conditional upon the granting of the prayer by the divinity, whereas in the d. the sacrifice comes first and binds the gods to their obligation. Livy (VIII, p. 6 ff.) has transmitted the typical formula, which reflects this conception of the d., a formula suggested and prepared by the pontiff.
Alongside the d. of public value were particular devotiones, which anyone could perform, in substitution for or for the benefit of another, as in the devotiones pro salute principis, frequent during the Roman Empire. As for the particular formulas of d. directed against individuals, V. DEFISSIONE.