For several weeks in the summer of AD 61, Queen Boudicca, whose name translates as ‘Woman of Victory', had known nothing but the satisfaction of brutal revenge.
Camulodunum (Colchester), the de facto capital of the Roman province of Britannia, was sacked, the colonists massacred or later sacrificed despite a heroic 'last stand' of veterans. Part of the Ninth Legion, some 2000 men, marching to the relief of the colony, was annihilated. Boudicca then turned her attention to Londinium (London), the burgeoning Roman emporium on the Thames.
On learning of the revolt, the Roman governor, Suetonius Paulinus, abandoned his conquest of the Isle of Mona (Anglesey) and marched directly for Londinium. Accompanied by his favourite legion, the Fourteenth, Paulinus reached the town before the rebels but realized the impossibility of defending it. He withdrew along Watling Street with those civilians who could keep up. Boudicca arrived soon afterwards and Londinium was destroyed. She then moved in pursuit of Paulinus. He bypassed Verulamium, which was also sacked by Boudicca's warriors.
Soon after the fall of Verulamium, Paulinus received reinforcements and looked for a place to halt Boudicca's advance.
Annals 14.34: the battlefield
Following the sacking of Verulamium, Tacitus tells us that Paulinus decided to halt his retreat and look for a place () to give battle. The bulk of the governor's small army was made up of the Fourteenth Legion and a vexillation (detachment) of the Twentieth Legion, which may also have accompanied him on his mission to London. The legionaries were reinforced by – auxiliary regiments in the immediate area or those that had joined Paulinus as he retreated. The army was now 10,000 strong, still a puny force compared to the vast host led by the queen of victory.