The Battle of Ticinus was fought between the Carthaginian forces of Hannibal and a Roman army under Publius Cornelius Scipio in late November 218 BC as part of the Second Punic War.

War had been declared early in 218 BC over perceived infringements of Roman prerogatives in Iberia (modern Spain and Portugal) by Hannibal.

The Romans were taken by surprise, but one of the consuls for the year, Scipio, led an army along the north bank of the Po with the intention of giving battle to Hannibal.

[5] Four years later, when Carthage was weakened by the mutiny of part of its army and the rebellion of many of its African possessions, Rome seized Sardinia and Corsica on a cynical pretence and imposed a further 1,200 talent indemnity.

[8][9] The contemporary Greek historian Polybius considered this act of bad faith by the Romans to be the single greatest cause of war with Carthage breaking out again nineteen years later.

[11] Carthage gained silver mines, agricultural wealth, manpower, military facilities such as shipyards, and territorial depth which encouraged it to stand up to future Roman demands.

[16] In 218 BC a Carthaginian army under Hannibal besieged, captured and sacked Saguntum[17][18] and early the following year Rome declared war on Carthage.

[19] Since the end of the First Punic War Rome had also been expanding, especially in the area of north Italy either side of the river Po known as Cisalpine Gaul.

In 218 BC the Romans pushed even further north, establishing two new towns, or "colonies", on the Po and appropriating large areas of the best land.

[22] In 218 BC the Romans raised an army to campaign in Iberia under the consul Publius Scipio, who was accompanied by his brother Gnaeus.

[30] The Carthaginians crossed the Alps with 38,000 infantry and 8,000 cavalry in October 218 BC, surmounting the difficulties of climate, terrain[25] and the guerrilla tactics of the native tribes.

His surprise entry into the Italian peninsula led to the cancellation of Rome's planned invasion of Africa by an army under Longus.

They also wished to obtain allies among the north-Italian Gallic tribes from which they could recruit, as Hannibal believed that he required a larger army if he were to effectively take on the Romans.

The local tribe, the Taurini, were unwelcoming, so Hannibal promptly besieged their capital, (near the site of modern Turin) stormed it, massacred the population and seized the supplies there.

[35][36] The modern historian Richard Miles believes that with these brutal actions Hannibal was sending out a clear message to the other Gallic tribes as to the likely consequences of non-cooperation.

[note 3] Believing he would therefore be facing a much larger Roman force than he had anticipated, Hannibal felt an even more pressing need to recruit strongly among the Cisalpine Gauls.

[38][39] Both commanders attempted to inspire the ardour of their men for the coming battle by making fiery speeches to their assembled armies.

[41] Next day each commander led out a strong force to personally reconnoitre the size and make up of the opposing army, about which they would have been almost completely ignorant.

[42][43] Anticipating an engagement as he closed with the Romans, Hannibal had recalled all of his scouts and raiding parties[44] and took with him an exclusively cavalry force which included almost all of his 6,000-strong mounted contingent.

[45][46] Iberia also provided experienced cavalry: unarmoured close-order troops[47] referred to by the ancient historian Livy as "steady", meaning that they were accustomed to sustained hand-to-hand combat rather than hit and run tactics.

[48] Most male Roman citizens were liable for military service and would serve as infantry, with a better-off minority providing a cavalry component.

Approximately 1,200 of the infantry in each legion, poorer or younger men unable to afford the armour and equipment of a standard legionary, served as javelin-armed skirmishers, known as velites.

The Roman light infantry, realising they would be cut down if the Carthaginians came into contact with them, turned and fled, making no attempt to throw their missiles.

[note 6] They were obstructed by the large number of their infantry attempting to pass through their ranks to the rear, and in the case of the Gallic cavalry, possibly by still having a javelinman riding into battle behind each of the cavalrymen.

[63] The cavalry did not move into contact at speed, but at a fast walk or slow trot; any faster would have "ended in a growing pile of injured men and horses", according to the modern historian Sam Koon.

The next morning the Carthaginian cavalry bungled their pursuit and the Romans were able to set up camp on an area of high ground by the river Trebbia at what is now Rivergaro.

[75] Scipio waited for reinforcements while Hannibal camped at a distance on the plain below and gathered and trained the Gauls now flocking to his standard.

[76] When Longus arrived in December, Hannibal enticed him into attacking and heavily defeated him at the battle of the Trebia; only approximately 10,000 of the Roman army of 40,000 were able to fight their way off the battlefield.