Julius Caesar was the first Roman to bring an army to Britain in 55 and 54 BC, but he did not stay. It was the emperor Claudius who finally invaded Britain in AD 43 and made it part of the Roman Empire.
The Romans introduced the Roman way of life. They built towns, villas and roads, and introduced their language, Latin. While some people in Britain followed a Roman lifestyle, others continued with the Iron Age way of life which had existed in Britain before the Romans invaded.