During the early stages of the revolt against the Roman occupation led by Boudica, the Queen of the Iceni, in 60, Paulinus was waging a war against the druids on Mona and had left only a skeleton force of old soldiers.
The Fourth Doctor and his companion Leela encountered Boudicca in the midst of the revolt. In order to prevent Boudica from severing the Doctor's head, Leela told her that the Doctor was a prophet who foresaw her defeat at the hands of the Romans. The Doctor told her that the forces at the Camulodunum were a decoy and Paulinus had stationed an army to the north and intended to attack Boudica's army while it was ransacking Camulodunum. However, this was not the case. There was no army to the north.
After the burning of Camolundunum, the Iceni and their allies marched to Londinium and slaughtered almost everyone in the city including the old, the weak and the infirm. Boudicca was eventually defeated by Paulinus' army in a field in the middle of England which no has ever been able to identify. Her army may have numbered up to 80,000 by this time but the Doctor notes that this figure could have been exaggerated by later historians. There were no survivors. Instead of allowing the Romans to execute her, Boudica killed her daughters before killing herself. The Doctor told Leela that he had no desire to to witness Boudica's defeat first hand. (AUDIO: The Wrath of the Iceni)