History: London, England, United Kingdom

With the collapse of Roman rule in the early 5th century, London was effectively abandoned. However, from the 6th century an Anglo-Saxon settlement known as Lundenwic developed slightly to the west of the old Roman city, around what is now Covent Garden and the Strand, rising to a likely population of 10–12,000. In the 9th century London was repeatedly attacked by Vikings, leading to a relocation of the city back to the location of Roman Londinium, in order to use its walls for protection. Following the unification of England in the 10th century London, already the country's largest city and most important trading centre, became increasingly important as a political centre, although it still faced competition from Winchester, the traditional centre of the kingdom of Wessex.
th century King Edward the Confessor re-founded and rebuilt Westminster Abbey and Westminster, a short distance upstream from London became a favoured royal residence. From this point onward Westminster steadily supplanted the City of London itself as a venue for the business of national government.
Following his victory in the Battle of Hastings, William the Bastard, Duke of Normandy, was crowned King of England in the newly finished Westminster Abbey on Christmas Day 1066. William constructed the Tower of London, the first of the many Norman castles in England to be rebuilt in stone, in the southeastern corner of the city to intimidate the native inhabitants. In 1097, William II began the building of Westminster Hall, close by the abbey of the same name. The hall became the basis of a new Palace of Westminster.
During the 12th century the institutions of central government, which had hitherto accompanied the royal court as it moved around the country, grew in size and sophistication and became increasingly fixed in one place. In most cases this was Westminster, although the royal treasury, having been moved from Winchester, came to rest in the Tower. While the City of Westminster developed into a true capital in governmental terms, its distinct neighbour, the City of London, remained England's largest city and principal commercial centre and flourished under its own unique administration, the Corporation of London. In 1100 its population was around 18,000; by 1300 it had grown to nearly 100,000.