Londinium was a settlement established on the current site of the City of London around AD 43. Its bridge over the River Thames turned the city into a and major, serving as a major commercial centre in Roman Britain until its abandonment during. Following in the mid-1st century, early Londinium occupied the relatively small area of 1.4 km, roughly equivalent to the size of present-day Hyde Park, with a fortified garrison on one of its hills.