The Sacrifice of Publius Decius Mus

Publius Decius Mus recounts his prophetic dream to his troops during the Latin War by Jacob Matthias Schmutzer, 1733-1811, (PD)

Defend the belief that a public assembly ought to be kept pure, the Campus Martius holy, the body of every Roman citizen undefiled, and the right of liberty unassailable.  M. Tullius Cicero.  Speech before Roman Citizens on Behalf of Gaius Rabirius, Defendant, Against the Charge of treason.  Section 11.

According to Livy, during the Latin War, as the army marched near Capua, it was given to the two consuls in mutual dreams that the army whose general pledged himself and his foemen's host to the Dii Manes and Earth, would be victorious. Upon confirmation from the haruspices the two divulged a plan to their senior officers and their army, that they may not lose heart, for they intended that whosoever's wing should falter first, should so pledge his life to the gods of the underworld and the Earth.

Once the battle was engaged, the left wing began to falter and Decius Mus called upon the Pontifex Maximus, M. Valerius, to tell him the means by which to save the army. The pontifex prescribed the required ritual acts and a prayer (for which see devotio). After performing the religious ritual, the fully armored Decius Mus plunged his horse into the enemy with such supernatural vigor and violence that the awe-struck Latins soon refused to engage him, eventually bringing him down with darts. Even then, the Latins avoided his body, leaving a large space around it; and so the left wing of the Romans, once faltering, now swept into this weakness in the enemy lines. Manlius, conducting the right wing, held fast, allowing the Latins to use up their reserves, before crushing the enemy host between the renewed left and Samnite foederati at their flank, leaving only a quarter of the enemy to flee.