The Romans established the town of Londinium shortly after their invasion of Britain in 43AD. In the second century, the city became capital of Roman Britain as the population reached 60,000. The Romans built the London wall, which was 6m tall and 2.5m thick, and survived for 1,600 years. The Roman occupation of Britain ended in 410, and the city went into a steep decline. Viking raids and occupation persisted until the tenth century, when the Anglo-Saxons took over. After the Norman Conquest William the Conqueror was crowned the King of England in 1066. A fairly stable monarchy followed, that continues to this day.
London became an important trading center and began to grow rapidly. In the Middle Ages, it was a dirty and crowded place (London actually remained quite dirty until the Clean Air Act of 1956). The Black Death killed more than half the city’s population in the mid-fourteenth century, and periodic bouts of the Plague, and other nasty diseases, affected the city for centuries. In 1666, the Great Fire of London lasted five days and destroyed 60% of the city. This accelerated the outward expansion from the city of London towards outlying districts. Despite those setbacks, London continued to grow. The city emerged on the world stage as England began expanding its empire overseas in the sixteenth century. By 1700, the population surpassed half a million.
Rapid growth continued in the eighteenth century as the Industrial Revolution dawned. The city’s first police force began operations in 1750. Factories began to sprout up around the city. London became the biggest city in the world at the start of the nineteenth century, as the population reached 1,000,000. Most of its citizens lived in abject poverty and London became notorious for its soot and smog. The nineteenth century also saw the rise of railroads. This facilitated the continued outward growth of the city. In the 1850s, work began on the world’s first underground railway, what would become the London Underground.
The British Empire reached its zenith at the start of the twentieth century. London’s population had reached more than 6 million, and residents from all over the world made it the first truly global city. The city survived World War I unscathed, but World War II brought the German Blitz. It left 30,000 people dead and destroyed huge swaths of the city. Londoners were resilient though, and soon enough life returned to normal. After the war, Britain lost what remained its empire, and though London no longer has the global importance it once did, it remains a world-class and cosmopolitan city.