Londinium was the name of the settlement established by the Romans around AD 43, which later became known as London. It was strategically located on the banks of the River Thames, making it an important trading and administrative center in Roman Britain. The city featured a grid layout, with roads leading to various parts of the Roman Empire. Over time, Londinium grew in size and significance, becoming a hub for commerce and culture. The remnants of its history can still be seen today, including structures like the Roman Wall and the London Bridge. Londinium laid the foundation for modern London, influencing its development for centuries.