The Romans invaded Britain in order to gain access to its mineral wealth and agricultural fields, and to prevent a regrouping and counterattack by the recently-conquered Gauls who had escaped the Roman armies by fleeing to the island. Roman military leaders were often enthusiastic about conquering new territories because it provided them with wealth that could be used to pay for the loyalty of their troops and to bribe officials back in Rome to further their careers. Although Julius Caesar's first two invasions between 55 and 54 B.C. were primarily intended as a preemptive strike against a Gaulish stronghold on the inland, it was not until about 100 years later that a full-scale Roman invasion led to an occupation that lasted almost 400 years.
The territory taken control of by the Romans in Britain was conquered during an initial period lasting about 40 years. A lack of coordination between the various military leaders commanding defensive forces on the island, coupled with the invading army's superior tactics, favored the Roman conquest and led to a rapid Romanization of the new territories. The Romans introduced their construction, agricultural and mining methods to Britain and set up a town-based government system with prosperous villas and economic centers. Existing within their empire as a western province, Roman influence at its peak extended to about 3/4 of the island of Great Britain.