The area was a stronghold for the Celtic Tribes, just to the east of St Ives were the lands of the Iceni in what is now Norfolk and Suffolk. Although it would appear the Romans quickly subjugated the tribes on dry land building a small town at Godmanchester a few miles to the north, the fen was a different story.
The tribes of the fen were both hard to find and even harder to defeat, continuous skirmishes eventually led to the Romans mounting a campaign to end the wars once and for all. Little did they know at the time they were about to be nearly wiped out themselves. In one such skirmish Prasutagus, the king of the Icenians, was killed and the Romans inflicted much damage. The Iceni however we not brought under control, they rose up against the Romans under the leadership of Prasutagus' wife Boudicca.
What followed next is as they say history, the Romans brought in enough military strength to quell the revolt and peace was finally achieved, at least until around 450AD. Very few Roman artefacts have been found in St Ives.