London was founded by the Romans at a convenient crossing of the Thames, though it had been convenient for the local inhabitants too. Tacitus describes a flourishing trading city existing in AD 67. The area was marshy but there was a low hill, roughly where the Bank of England now stands and it was here that the Romans chose to build a typical Roman city, primarily for military reasons.
England at that time was inhabited by a hodge-podge of tribes and small kingdoms, and the Romans had little difficulty subduing them - despite some noble efforts at defense. The locals assimilated Roman culture, and after a couple of hundred years were more Roman than the Romans. When the Romans pulled out, pressured by frontier wars, the Saxons took over. They hated living in the old walled Roman city and established their own city of long huts, roughly where Covent Garden is today.
By the time the Normans took over from the Saxons, the basis of the mercantile capital was already laid through a charter of citizen’s rights and a confederation of tradesmen, providing a counterweight to the aristocracy. London was a leading trading port of Western Europe wherein merchants from Italy, the Netherlands, France and Germany lived around the river it had only one crossing -the Old London Bridge, until 1769.
By the late 16th century, the seeds of England’s future as a world trading power were sown with the formation of the Trading Companies - The East India Company, The Muscovy Company the Levant Company, and the Turkey Company, which along with Britain’s naval prowess, saw management techniques still venerated by world corporations, conquer the world.
The Plague in 1665 and the fire in 1666 shook London out of its contentment but also lead to a wave of property development that saw the forerunners of Sir Richard Rogers dominating the city skylines.
The redevelopment went on into the 18th Century, seeing buildings like The Bank of England and most of the Bridges across the Thames springing up. The Victorians supervised the transformation of London into a modern city, sewers and underground railways tunneled beneath the clay of the world’s capital, while over ground railways and omnibuses opened up across the city, and the port of London enjoyed a final flowering.
Despite the presence of the Royal Palaces, Westminster Abbey (a place of pilgrimage) and the country’s first printing presses, Westminster really only came into its own in the 19th century, and was granted the title of a City, with its own mayor in 1900.
The two World Wars saw huge destruction, to both the populace and the city and some terrible rebuilding followed, with little real conservation work. London's architectural revival started with the completion of the Lloyd's building by Sir Richard Rogers in 1979. London is beginning to rival Paris in its Grand Projects.