The area around Westminster was first inhabited in 55 BC, after the Roman invasion of Britain under the command of Julius Caesar, who called the city Londinium. Following the fall of Roman Empire and the invasion of the Anglo-Saxons it became the capital of the Kingdom of Essex. In the 9th century, thanks to Danish traders, the city was transformed into England's primary urban centre. In 1066, William the Conqueror was crowned king at Westminster Abbey and the Tower of London was built. In the following centuries, London held the title of the capital city, though it only officially became the capital of the UK at the end of the 1800s. From the 14th century onwards, London has continued to grow into a vast metropolis, reinforcing its role as the centre of English political, financial, social, and cultural life.