When the Sixth Century had halved the distance to the fortifications Cato glanced back again and was shocked to see that the enemy were almost upon them. Ahead, on either side of the track, lay the defensive ditch, strewn with sharpened stakes. Then the earth rampart, where the rest of the cohort leaned over the palisade, shouting desperate encouragement to their comrades. Cato realised that he and his men weren’t going to make the gate before the enemy crashed into them.

‘Halt! Form up to the rear!’

Even with the open gate tantalisingly close to them the men of the Sixth Century readily obeyed the order. They quickly turned, raised their shields and closed ranks into a compact defensive formation. But this time, when the enemy charged home, the legionaries reeled under the impact. The line of shields was driven in, sending one of the men sprawling back. Before anyone could step into his place a huge Celtic warrior burst in amongst them, whirling an axe over his head. An instant later it swept down towards the legionary who had been thrown back on to the ground. He saw the blade coming and threw up an arm to protect his face. The axe barely shuddered as it cut clean through the man’s forearm, shattered his helmet and buried itself deep in his skull.

‘Take him down!’ Cato screamed hoarsely. ‘Kill him!’

Three swords thrust into the warrior and he gave an explosive grunt and sagged to his knees, the deadly axe dropping from his nerveless fingers as he died. But before the gap he had forced in the Roman line could be filled, another warrior leaped forward and landed astride his fallen comrade, slashing at the nearest legionary with his long sword. The Roman just managed to turn enough for the blow to land on the shoulder of his segmented armour and there was a dull crack as his collarbone shattered under the impact.

More enemy warriors burst in amongst the men of the Sixth Century, and Cato knew that any formation was no longer possible. He thrust himself forward into the dense brawl, pushed up against the back of one of his men and braced his legs to help heave the man forwards. But the pressure from the enemy warriors was irresistible, urged on by Caratacus, roaring his encouragement. Cato felt himself being forced back, step by step, until the century was astride the ditch and the ramparts loomed up behind him. The man in front of him shuddered, convulsed and then fell to the side, into the ditch and was impaled on the sharpened stakes lining the bottom. Then Cato was in the middle of the fight, crouching low, shield close and sword held horizontal, ready to thrust.