The Third Samnite War had thrown up a formidable coalition of Etruscans, Samnites, Umbrians and Gauls against Rome. When Rullianus was unanimously called to the consulship, he stipulated as a condition for accepting that Mus again be his colleague so in 295 BC Mus was elected to a fourth consulship. While Mus was first stationed in Samnium, events up north dictated that both Roman armies be united to face the enemy. When the armies clashed near Sentinum, Publius Decius Mus commanded the left wing of the Roman army. Faced by the Gauls, his troops started giving way under their attacks and Mus followed the example of his father performing a ritual called the Devotio, thereby dedicating himself and the enemy army to the gods of the underworld, then rushing the enemy where he fell in the battle.