were a few soldiers that had been left in the valley of the Po to
restrain the Gauls, who had recently shown signs of defection.

Publius Cornelius Scipio, upon his return from Massilia, took command
of these. He met Hannibal first in October, 218, near the river
Ticinus, a tributary of the Po. A cavalry skirmish followed, in which
he was wounded and rescued by his son, a lad of seventeen, afterwards
the famous Africanus. The Romans were discomfited, with considerable
loss.

They then retreated, crossing the Po at Placentia, and destroying the
bridge behind them. Hannibal forded the river farther up, and marched
along its right bank until he reached its confluence with the Trebia,
opposite Placentia. Here he encamped.

Meanwhile Sempronius, who had been recalled from Sicily, relieved the
disabled Scipio.

Early one raw morning in December, 218, the vanguard of the
Carthaginians was ordered to cross the Trebia, and, as soon any
resistance was met, to retreat. The other troops of Hannibal were
drawn up ready to give the enemy a hot reception, if, as he expected,
they should pursue his retreating vanguard. Sempronius was caught in
the trap, and all his army, except one division of 10,000, was cut to
pieces. The survivors took refuge in Placentia and Cremona, where they
spent the winter. Sempronius himself escaped to Rome.

The result of TREBIA was the insurrection of all the Celtic tribes in
the valley of the Po, who increased Hannibal's army by 60,000 infantry
and 4,000 cavalry. While the Carthaginian was wintering near