The peace made with the Samnites in 304 b.c. lasted for six years, after which the third war with these hardy mountaineers began.
One of the Consuls at this time was Cornelius Scipio, the great-grandfather of the famous Scipio who conquered Hannibal.
Now the Samnites had persuaded the Gauls to join them in their new attack upon Rome, and they, it is said, surprised and slew one of Scipio's legions. So dreadful was the slaughter that not a single soldier escaped to tell the Consul, who was some distance off with the main body of his army, what had happened.
Nor did the Romans know what had befallen their comrades, until the Gauls, elated with victory, galloped up to the camp of the enemy shouting their war-cries and carrying on the point of their lances the heads of those whom they had slain.
In 295 b.c. the Romans grew alarmed at the forces that had united against them, for the Samnites had now not only the Gauls, but also the Etruscans and other tribes to strengthen them.
Fabius, whose courage had been tested in many a difficult position, was therefore appointed Consul for the fifth time, and sent with his colleague Decius to the war.
The leader of the Samnites, Egnatius, was at Sentinum in Umbria. He was anxious to fight without delay, for he knew how quickly the Gauls were used to desert their allies.
So he, as well as his men, was pleased when they saw that the Roman legions, with the two Consuls at their head, had reached Sentinum.
Yet for two days no battle took place. But as the armies faced one another, a stag chased by a wolf ran in between the two forces.
The Gauls, in their barbarous way, threw their javelins at the stag and killed it, while the Romans allowed the wolf to run safely through their ranks, for the beast was sacred to Mars, and its presence was to them a sign of victory.
"The Gauls have slain the stag which is sacred to Diana," cried the Roman soldiers. "It is certain that her wrath will fall upon them. As for us, the wolf bids us remember Quirinus, our divine founder. With his aid we have naught to fear."
The Consuls could no longer restrain the eagerness of their legions, and they at once led them against the enemy.
Fabius commanded the right wings, and faced the Samnites; Decius was opposite the Gauls. They, as was their way, rushed with loud war-cries upon the foe, spurring their horses forward with fury and driving their war-chariots upon the Roman cavalry.
Startled by the noise of the heavy chariots and by their strange appearance, the Roman horses turned and fled. In their flight they encountered the infantry, and dashing upon it, caused the legions to give way.
Decius tried in vain to rally his men. Then, in despair, he determined to do as his father had done, and yield himself up to death, that the army might be saved.
So, spurring his steed, he rode headlong into the midst of the Gallic warriors and was slain.
The soldiers, seeing that the Consul had sacrificed himself for their sake, took courage and turned to face the foe. Decius had, by his death, won a victory for his country.
Fabius meanwhile, had routed the Samnites, who now added to the confusion by rushing past the Gauls, in a desperate effort to reach their camp.
As the Samnites fled, the Gauls formed themselves into a dense mass, for they feared that they would now be attacked by Fabius.
The Consul, however, contented himself by sending a detachment of his men to harass the Gauls in their rear, and another to attack them in front.
Then vowing to build a temple to Jupiter and to offer him all the spoil if he was victorious, Fabius himself followed the Samnites and cut them down ruthlessly, until at length Egnatius, their brave commander, fell. Resistance was now at an end, yet those who were still alive refused to surrender. Forming themselves into a compact body, they marched away and struggled back to their own country.
The Gauls too were utterly crushed, and the glory of the battle of Sentinum belonged to Rome.