Despite the harsh winter conditions of this northern climate, Plautius had kept his cavalry active and sent them on long marches deep into the heart of the island, with strict orders to observe and not engage the enemy. Nevertheless, some patrols had run into ambushes, leaving only a few frightened survivors to report on their fate. Other patrols had disappeared entirely. Such losses were a serious matter for an army already deficient in cavalry, but the need for intelligence of Caratacus and his forces was urgent. As far as General Plautius and his staff could discover, Caratacus had retreated up the Tamesis valley with what was left of his army. There the King of the Catuvellauni had set up a number of small forward bases from which detachments of chariots and light horse were raiding into the territory held by the Romans. A number of supply columns had been intercepted and their food and equipment carried off, leaving behind only the smouldering remains of wagons and the butchered bodies of the escorting troops. The Britons had even succeeded in sacking a fort guarding the crossing on the Mead Way, and burning the pontoon bridge erected there.

These raids would have a minimal impact on the ability of the legions to fight the coming campaign, but they boosted the morale of the Britons and this was a concern at headquarters. Many of the tribes who had so eagerly embraced a treaty with Rome the previous autumn were now cooling their relationship. Large numbers of their warriors had joined with Caratacus, sickened by the alacrity with which their leaders had bowed to Rome. Spring would find Plautius and his legions facing a fresh British army.

His experiences the previous year had taught Caratacus much about the strengths and weaknesses of the Roman forces. He had seen the iron firmness of the legions and would no longer hurl his brave warriors headlong onto a wall of shields they could not hope to break. The hit-and-run tactics he was currently employing were a worrying indication of the shape of the coming conflict. The legions might well be masters of the battlefield, but their slowness would make it easy for the British forces to slip round and through them and create merry havoc with their supply lines. The Britons would no longer be so foolish as to stand and fight the legions. Instead they would sidestep each thrust and whittle away at the flank and rear of the Roman forces.

How, Vespasian wondered, could the legions deal with such tactics? Pinpointing and destroying Caratacus and his men would be rather like trying to sink a cork with a hammer. He smiled bitterly at the simile; it was too accurate a comparison for comfort.

‘There!’ General Plautius pressed his ring down on the last document. The clerk whisked it away from the table and tucked it under his arm with all the others.