Between 1642 and 1645, London was the heart of a national revolution against absolutism.

During the ‘December Days’ in late 1641, the political crisis in relations between Court and Parliament tipped over into revolution. Vast crowds of ordinary Londoners besieged Parliament to force through the anti-royalist measures they supported. Then, in early January 1642, an attempted coup by the Court backfired. King Charles entered Parliament to arrest opposition leaders, only to discover ‘that the birds had flown’.

They had ‘flown’ into the City, where gates were shut, portcullises lowered, and chains put across streets. For several days, thousands of men stood armed and ready, and women boiled water ‘to throw on the cavaliers’.

But the cavaliers never came. Charles fled the capital on 10 January, and London became a revolutionary city in armed revolt against King and Church.

London was the country’s chief port and financial centre, the seat of government, and, with the Tower of London, the nation’s chief arsenal. Charles’s flight at the beginning of the war therefore placed his cause at a distinct disadvantage. To many Parliamentarians, it was obvious that the King would attempt to regain the capital by force.

So, between the autumn of 1642 and the spring of 1643, an 18km circuit of forts and bulwarks connected by ramparts and ditches was thrown up around London. It was the largest feat of military engineering undertaken anywhere in the country during the conflict, and at the time the circuit was among the largest urban defence systems in Europe.

The map below shows a detailed plan of the Parliamentarian defences around London, drawn by George Vertue in 1738.

The full article can be seen in issue 24 of Military History Monthly.

KEY

EAST

1. Bulwark and half-bulwark: Gravel Lane

2. Hornwork: Whitechapel Road

3. Redoubt and two anks: Brick Lane

4. Redoubt and four anks: Hackney Road

5. Redoubt and four anks: Kingsland Road

NORTH

6. Battery and breastwork: Mountmill

7. Battery and breastwork: St John Street

8. Small redoubt: Islington Road

9. Large fort and four half-bulwarks: Upper Pond, New River

10. Battery and breastwork: Blackmary Hill

11. Two batteries and breastwork: Bedford House

12. Redoubt and two anks: St Giles Road

13. Small fort: Tyburn Road

14. Large fort and four half-bulwarks: Wardour Street

15. Small bulwark: Oliver’s Mount

16. Large fort and four bulwarks: Hyde Park Corner

WEST

17. Small bulwark and battery: Constitution Hill

18. Court of Guards: Chelsea Turnpike

19. Battery and breastwork: Tothill Field

SOUTH OF THE THAMES

20. Quadrant fort and half-bulwarks: Vauxhall

21. Fort and four half-bulwarks: St George Field

22. Large fort and four bulwarks: Blackman Street

23. Redoubt and four anks: Kent Street