When the Romans left (to defend Rome against the German Vandal tribe) the German Saxons moved in.Being basically rural peoples they had no use for towns and London was abandoned.Looking back at the History of England's capital from before the Romans arrived right up to the present day.
Starting in the west at present day Blackfriars Bridge walk north only about 200 yards to "Ludgate" (now Ludgate circus).Also of course the comforts they were used to including: Olive oil, wine, dates, figs and salted fish.The containers would have been the typical earthenware jars of the day called Amphorae.The Saxons chose Winchester just north of present day Southampton as their base.
It was not until some 200 years after the departure of the Romans (about AD 670) that the London area was reoccupied (by the Saxons) to any effective level and it was in a new area around present day Charing Cross and Trafalgar Square that was to be their base for their new city and port.
(Note the present day embankment did not exist.) The only building of note in the old Roman area which was used by the Saxons was the site of St Paul's for a church of that name.