‘I know that, damn you,’ Cato snapped. ‘I’ll thank you not to question my orders, Centurion. Now have the men form up. And watch the pace I set. I will not have any man race ahead, nor lag behind. We will reach the battlefield as one. It’s our best chance of survival. Is that clear?’

Stellanus gritted his teeth and nodded, before turning to repeat the order. ‘Form line!’

The two squadrons wheeled to the left and spread out along the slope. Cato looked down and saw that there were perhaps three hundred paces of steep ground to negotiate before it was sufficiently level to give the order for the charge. There would be no mad scramble across the open ground as with the cavalry charges of less disciplined armies. Roman cavalry were strictly drilled and the charge was a carefully graduated build-up in speed. They would only unleash their mounts and let them gallop the last fifty paces to contact with the enemy. Even so, the advance down the slope would need to be carefully handled to keep the formation together.

Glancing to both sides, Cato saw that the two squadrons were ready, the men clutching their spears and holding their shields close. The tails of their mounts flicked and some of the horses tossed their heads, sensing the tension of the riders. Cato held his spear aloft. ‘Hold the line. When the order is given to charge, don’t stop until you reach the column . . . Blood Crows, forward!’

Hannibal started down the slope at a walk. As they descended, Cato looked ahead to see that the swiftest of the enemy had reached the reinforcements while they were still deploying into a box around the baggage train. The first Silurians were easily dealt with, but as more and more charged home, the legionaries at the front of the column were not able to complete their change of formation and a disordered battle line rapidly fringed the carts and wagons huddled in the middle. The cavalry squadron, a short distance away, spurred forward into the fight and was engulfed by the horde of Silurian warriors closing round the Roman column.

At the foot of the slope the infantry who had been shadowing the Thracians stopped and turned to face their opponents. In amongst them Cato could see some of the dark cloaks of the Druids who shouted encouragement to the warriors and hurled curses and spells at the oncoming horsemen. As the slope began to ease, Cato called over his shoulder, ‘Form wedge on me!’