London – then Londinium – was established as the capital of England after the Roman conquest of Britain in AD43, led by the Emperor Claudius.
Towards the end of the second century, a wall was constructed to enclose the growing metropolis and protect its 50,000 inhabitants from raiders – the city was sacked by Boudicca (often known as Boudacia – her statue stands at Westminster) in AD60 and the Picts had overrun the north of England in 180s.
London Wall was about two miles long, enclosing an area of about 330 acres. The wall stood about twenty feet high and eight feet thick and had bastions – or guard towers – every seventy yards. Some portions of the wall and a bastion, still exist, having survived the Blitz of 1940, the Great Fire of 1666 and two thousand years of development. The best preserved portions can be seen near Tower Hill underground station and along the road that takes the name ‘London Wall’.
There were originally six gates in the Roman wall – clockwise from Aldgate in the east – Aldgate, Ludgate, Newgate, Aldersgate, Cripplegate and Bishopsgate. A seventh gate – Moorgate – was constructed in 1415 between Aldersgate and Cripplegate.
The names of the ancient gates are still evident in London’s geography – both Aldgate and Moorgate now give their names to London Underground stations while all the gates can be found in the names of streets in the appropriate areas.