Battle of Sentinum The Battle of Sentinum ( 295 BC ) was the decisive battle of the Third Samnite War , fought in 295 BC near " Sentinum " ( now next to the town of Sassoferrato , Italy ) , in which the Romans were able to overcome a formidable coalition of Samnites , Etruscan s , Umbri ans , and their Gallic allies . The result was a decisive victory for Rome , allowing it to unify Central Italy . The Romans were commanded by consuls Publius Decius Mus and Fabius Maximus Rullianus , and amounted to about 40 , 000 men : 4 legions , a strong contingent of Roman cavalry , 1 , 000 elite cavalry men from Campania , 4 allied and Latin legions and a strong contingent of allied and Latin cavalry . Their opponents were Samnites and Gauls , since the Etruscans and the Umbrians had returned to their territories to defend them from another small Roman army . Following their defeat at the battle of Tifernum , the Samnites realised that they could not defeat Rome alone and so persuaded the Etruscans , Senones Gauls and Umbrians to join a coalition to finally stop the growing Roman dominance over Italy . The Roman attempt to prevent the Samnites marching north to link up with the Gauls was defeated near Camerinium The combined army of 80 , 000 men far outnumbered the 40 , 000 men in the Roman one , commanded once again by the consuls Fabius Rullianus and Decius Mus and including an elite force of 1 , 000 Campanian cavalry . The Romans sent a small garrison to raid Etruria and Umbria : this had the desired effect of drawing these contingents away to protect their homeland . With the Samnite / Senones army now down to 50 , 000 troops the Romans offered battle . The two armies arrived at the Plain of Sentinum but waited for two days to battle each other . Finally , unable to control the eagerness of their troops , the Romans attacked . Fabius faced the Samnites ; Publius Decius was opposite the Gauls . The Roman line initially buckled under the Gauls ' chariot s . Mus charged into the Gauls anyway . Although he was slain , Mus ' charge inspired his men and they restored the Roman line . Fabius routed the Samnites and then outflanked the Gauls to win the battle . The battle opened with a ferocious attack by the Gauls on the Romans under Publius Decius Mus . Publius Decius Mus responded with a cavalry charge which , although initially effective , was defeated by the Gallic chariots . With his army collapsing it is said that , like his father at the Battle of Vesuvius , Mus rode into the Gallic horde and died committing the Act of Devotio . This was enough to rally his men , and with Rullianus having driven off the Samnites on his half of the battlefield , Rullianus was able to commit his Triarii , Campanian Knights and part of the III Legion , under the Tribune Lucius Cornelius Scipio , into the flank of the Gauls . This was too much for the Gauls and they joined the Samnites in headlong retreat . Only 12 , 000 Samnites and Gauls escaped the slaughter in which 8 , 000 Romans and 25 , 000 Gauls and Samnites were killed . After a further series of defeats , the Samnites finally accepted Roman dominance in 290 BC . They would rise once more to join the campaigns of Pyrrhus on behalf of the Greeks of southern Italy , but with his defeat all the peoples of Italy were absorbed into the Roman commonwealth .