2nd Punic war
Hannibal's first winter in Italy
Hannibal in Italy
When Hannibal had arrived in Italy he needed two things first: Rest for his men and reinforcements. The first was not too difficult as long as he wasn't attacked. reinforcements were a different matter. Hannibal had come to Italy with the idea he would be welcomed as a liberator and all the peoples submitted to Rome would now choose his side. In fact his strategy (or his father's) was based upon this idea. This idea would prove to be wrong. In this stage even the Gauls, the only peoples in Italy revolting to the Romans weren't too eager to help Hannibal yet.
When consul P. Cornelius Scipio had established Hannibal had escaped him, he had put his brother Gnaeus in command and ordered him to proceed to Spain as planned. With a small group he returned to Marsilia and landed soon after in Pisae. Here he took over the command of the legions he had left there after the fights with the Gauls and marched to the point where he suspected Hannibal to show up. If we assume he left with a detachment on horse back, he will have needed 2 days to reach Marsilia and 2 days more to reach Pisae by sea and for Placentia and the Ticinus 12 days more. So he needed 16 days where Hannibal needed 25.
Communication is the keyword here
Soon hereafter the Roman senate decided to recall the other consul Ti. Sempronius Longus, who was already on Sicily at that moment, preparing an invasion to Carthago.
To Pisae over land is a distance of approximately 1200 km.
- A messenger on horseback would need 60 hours riding time (20km/h) if he could change horses and maybe the messenger. That would take him in about a week from Pisea to Lilibaeum.
- An army on foot could do about 25 km/day, which would take 48 days to cover the full distance, but if we follow Polybius via Roma and Ariminium it would have been 1750 km = 70 days. True, an army can do 50 km a day, but only for a short period and certainly not through the mountainous terrain the Romans had to pass. The peace with Samnium was still fresh, so Sempronius would have kept the Roman discipline of building a camp every day, which will have taken 1 to 2 hours every day. We must rule out the possibility of Sempronius coming all the way on foot.
-By sea 900 km to Pisae. We must consider sea fare was still made in sight of the coast. With an approximate speed of 7,5 km/h that would take 120 hours of rowing time. The nights still had to be spent ashore, so that would take about 12 days.
-From Pisae to Placentia still a walk of ten days.
Livius has Sempronius sail over the Adriatic to Ariminium. That would have been a distance of 2000 km = 27 days. From Rimini to Placentia 270 km = 11 days. In total 38 days. This would have brought Sempronius near Placentia circa december 10. Still in time for the battle.
So if we consider only the fasted way of movement, and grant the senate 2 days for making a decision, the time between Scipio's landing in Pisae and the arrival of Sempronius 7+12+2+10= 31 days, a full month! A look at the schedule below shows the communications between senate and armies must have been superbe.
Battle at the Ticinus
As we can see Scipio had time enough to post sentries along the river Po. He took all his cavalry (probably the 600 Romans and his spear carrying infantrymen, again probably his velites. He had a (ship) bridge built across the Ticinus and moved with his reconnaissance party to the west.
Hannibal rode along the north side of the river as well with his 6000 horses. Without hesitation Hannibal attacked with his forces being 10:1. Scipio tried to position his velites but they were no match for this mass of horses. Scipio had his detachment retreat after the Ticinus and the bridge destroyed. Scipio himself got wounded and there are some claims he was rescued by his son Publius. But that may well have been entered in the annals to boost his son's prestige even more.
Hannibal made some hundred or so prisoners turned west again and found a place where he could cross the Po.
Triumph is all important
Scipio moved east crossed the Po and built his camp on the east bank of the Trebbia. When Hannibal, who had had to make a detour to cross the PO neared from the west and offered battle to Scipio, the latter crossed the Trebbia and built his can a couple of kms up stream. Hannibal built his camp a couple of kms north on the other bank.
Now Sempronius Longus arrived and built his camp near Scipio's. It will have been half December and the end of his consulship was nearing. If he wanted the very, very, very important triumph march through Rome, he needed to get his victory soon. Scipio tried and warned him to take his time and to have the attack delayed until spring. But that would mean, the attack would be lead by another consul.
Hannibal had some tricks on his sleeve and the battle of the Trebia was not to be the great success Sempronius had hoped for.