The Romans and Druids had first come into contact within the conquering of Western Europe. Though Rome had made peace with most of the tribes and settlements in England, they did not plan to do so with the Druids.
Druids were priests who were both respected and feared by the British. They were believed to have the ability to see into the future and acted as teachers and judges. It took up to 20 years to finally become a Druid and they were known to be very intelligent. However not much is known of what they studied as they were not allowed to write down any of their knowledge.
Druids were very religious in an individual way which angered the Romans because of the human sacrifices made. Julius Caesar was especially shocked by this practice and we can tell from his writings what went on in the Druid ceremonies, though only from his perspective. The Romans themselves had once sacrificed people but now viewed it as barbaric and could not tolerate it, so vowed they would destroy the Druids.
Though the Romans needed to take caution as the Druids were not always in one place to be attacked with force - they travelled over England freely as the Britons were too afraid to stop them. In AD 54, the Druids were banned by Emperor Claudius, and in AD 60 the governor of England (Suetonius) made the decision to attack the Druids mainland of Anglesey. This was because of the hope that if the centre was destroyed, the Druid population in surrounding outskirts would die out more quickly. The Romans also destroyed any ceremonial sites in Anglesey used by the Druids, but many were in well hidden places and able to survive.
Roman foot soldiers had boats built for them while the cavalry swam across with their horses. The Druids hurled abuse at them but could not physically stop the Roman army from approaching.
"The Druids Relationship with The Romans". HistoryLearning.com. 2015. Web.