Location of Iceni territory within England, Wales and Mann; modern county borders for England and pre-1996 borders for Wales are shown for context.
Tacitus and Dio agree that Boudica was of royal descent. Dio says that she was "possessed of greater intelligence than often belongs to women", that she was tall and had hair described as red, reddish-brown, or tawny hanging below her waist. Dio also says she had a harsh voice and piercing glare, and habitually wore a large golden necklace (perhaps a torc), a many-coloured tunic, and a thick cloak fastened by a brooch.
Her husband Prasutagus was the king of the Iceni, the people who inhabited roughly what is now Norfolk. They initially were not part of the territory under direct Roman control, having voluntarily allied themselves to Rome following Claudius' conquest of 43 CE. They were proud of their independence, and had revolted in 47 CE when the then-governor Publius Ostorius Scapula threatened to disarm them. Prasutagus had lived a long life of conspicuous wealth and, hoping to preserve his line, made the Roman emperor co-heir to his kingdom, along with his wife and two daughters.
It was normal Roman practice to allow allied kingdoms their independence only for the lifetime of their client king, who would then agree to leave his kingdom to Rome in his will. For example, the provinces of Bithynia and Galatia, were incorporated into the Empire in just this way. Roman law also allowed inheritance only through the male line, so when Prasutagus died, his attempts to preserve his line were ignored and his kingdom was annexed as if it had been conquered. His lands and property were confiscated and nobles treated like slaves. According to Tacitus, Boudica was flogged and her daughters were raped. Cassius Dio says that Roman financiers, including Seneca the Younger, chose this time to call in their loans. Tacitus does not mention this, but does single out the Roman procurator Catus Decianus for criticism for his "avarice". Prasutagus, it seems, had lived well on borrowed Roman money, and on his death his subjects had become liable for the debt.
In 60 or 61 CE, while the current governor, Gaius Suetonius Paulinus, was leading a campaign against the island of Mona (modern Anglesey) in the north of Wales, which was a refuge for British rebels and a stronghold of the druids, the Iceni conspired with their neighbours the Trinovantes, amongst others, to revolt. Boudica was chosen as their leader. According to Tacitus, they drew inspiration from the example of Arminius, the prince of the Cherusci who had driven the Romans out of Germany in 9 CE, and their own ancestors who had driven Julius Caesar from Britain. Dio says that at the outset Boudica employed a form of divination, releasing a hare from the folds of her dress and interpreting the direction in which it ran, and invoked Andraste, a British goddess of victory.
The rebels' first target was Camulodunum (Colchester), the former Trinovantian capital and, at that time, a Roman colonia. The Roman veterans who had been settled there mistreated the locals and a temple to the former emperor Claudius had been erected there at local expense, making the city a focus for resentment. The Roman inhabitants sought reinforcements from the procurator, Catus Decianus, but he sent only two hundred auxiliary troops. Boudica's army fell on the poorly defended city and destroyed it, besieging the last defenders in the temple for two days before it fell. Archaeologists have shown that the city was methodically demolished. The future governor Quintus Petillius Cerialis, then commanding the Legio IX Hispana, attempted to relieve the city, but suffered an overwhelming defeat. His infantry was wiped out—only the commander and some of his cavalry escaped. The location of this famous destruction of the Legio IX is now claimed by some to be the village of Great Wratting, in Suffolk, which lies in the Stour Valley on the Icknield Way West of Colchester, and by a village in Essex. After this defeat, Catus Decianus fled to Gaul.
When news of the rebellion reached him, Suetonius hurried along Watling Street through hostile territory to Londinium. Londinium was a relatively new settlement, founded after the conquest of 43 CE, but it had grown to be a thriving commercial centre with a population of travellers, traders, and, probably, Roman officials. Suetonius considered giving battle there, but considering his lack of numbers and chastened by Petillius's defeat, decided to sacrifice the city to save the province.
...Alarmed by this disaster and by the fury of the province which he had goaded into war by his rapacity, the procurator Catus crossed over into Gaul. Suetonius, however, with wonderful resolution, marched amidst a hostile population to Londinium, which, though undistinguished by the name of a colony, was much frequented by a number of merchants and trading vessels. Uncertain whether he should choose it as a seat of war, as he looked round on his scanty force of soldiers, and remembered with what a serious warning the rashness of Petilius had been punished, he resolved to save the province at the cost of a single town. Nor did the tears and weeping of the people, as they implored his aid, deter him from giving the signal of departure and receiving into his army all who would go with him. Those who were chained to the spot by the weakness of their sex, or the infirmity of age, or the attractions of the place, were cut off by the enemy.
Londinium was abandoned to the rebels who burnt it down, slaughtering anyone who had not evacuated with Suetonius. Archaeology shows a thick red layer of burnt debris covering coins and pottery dating before AD 60 within the bounds of Roman Londinium, whilst Roman-era skulls found in the Walbrook in 2013 were potentially linked to victims of the rebels. Verulamium (St Albans) was next to be destroyed.
In the three settlements destroyed, between seventy and eighty thousand people are said to have been killed. Tacitus says that the Britons had no interest in taking or selling prisoners, only in slaughter by gibbet, fire, or cross. Dio's account gives more detail; that the noblest women were impaled on spikes and had their breasts cut off and sewn to their mouths, "to the accompaniment of sacrifices, banquets, and wanton behaviour" in sacred places, particularly the groves of Andraste.
While Boudica's army continued their assault in Verulamium (St. Albans), Suetonius regrouped his forces. According to Tacitus, he amassed a force including his own Legio XIV Gemina, some vexillationes (detachments) of the XX Valeria Victrix, and any available auxiliaries. The prefect of Legio II Augusta, Poenius Postumus, stationed near Exeter, ignored the call, and a fourth legion, IX Hispana, had been routed trying to relieve Camulodunum, but nonetheless the governor was able to call on almost ten thousand men.
Suetonius took a stand at an unidentified location, probably in the West Midlands somewhere along the Roman road now known as Watling Street, in a defile with a wood behind him — but his men were heavily outnumbered. Dio says that, even if they were lined up one deep, they would not have extended the length of Boudica's line. By now the rebel forces were said to have numbered 230,000, however, this number should be treated with scepticism — Dio's account is known only from a late epitome, and ancient sources commonly exaggerate enemy numbers.
Boudica exhorted her troops from her chariot, her daughters beside her. Tacitus gives her a short speech in which she presents herself not as an aristocrat avenging her lost wealth, but as an ordinary person, avenging her lost freedom, her battered body, and the abused chastity of her daughters. She said their cause was just, and the deities were on their side; the one legion that had dared to face them had been destroyed. She, a woman, was resolved to win or die; if the men wanted to live in slavery, that was their choice.
However, the lack of manoeuvrability of the British forces, combined with lack of open-field tactics to command these numbers, put them at a disadvantage to the Romans, who were skilled at open combat due to their superior equipment and discipline. Also, the narrowness of the field meant that Boudica could put forth only as many troops as the Romans could at a given time.
First, the Romans stood their ground and used volleys of pila (heavy javelins) to kill thousands of Britons who were rushing toward the Roman lines. The Roman soldiers, who had now used up their pila, were then able to engage Boudica's second wave in the open. As the Romans advanced in a wedge formation, the Britons attempted to flee, but were impeded by the presence of their own families, whom they had stationed in a ring of wagons at the edge of the battlefield, and were slaughtered. This is not the first instance of this tactic—the women of the Cimbri, in the Battle of Vercellae against Gaius Marius, were stationed in a line of wagons and acted as a last line of defence. Ariovistus of the Suebi is reported to have done the same thing in his battle against Julius Caesar. Tacitus reports that "according to one report almost eighty thousand Britons fell" compared with only four hundred Romans.
According to Tacitus in his Annals, Boudica poisoned herself, though in the Agricola which was written almost twenty years prior he mentions nothing of suicide and attributes the end of the revolt to socordia ("indolence"); Dio says she fell sick and died and then was given a lavish burial; though this may be a convenient way to remove her from the story. Considering Dio must have read Tacitus, it is worth noting he mentions nothing about suicide (which was also how Postumus and Nero ended their lives).
Postumus, on hearing of the Roman victory, fell on his sword. Catus Decianus, who had fled to Gaul, was replaced by Gaius Julius Alpinus Classicianus. Suetonius conducted punitive operations, but criticism by Classicianus led to an investigation headed by Nero's freedman Polyclitus. Fearing Suetonius' actions would provoke further rebellion, Nero replaced the governor with the more conciliatory Publius Petronius Turpilianus. The historian Gaius Suetonius Tranquillus tells us the crisis had almost persuaded Nero to abandon Britain.