The other thing about London is it’s ambiguously the capital of England because it predates England by hundreds of years and it wasn’t even intended to be the capital by the Romans. They built this lovely capital in Colchester, which got burnt down. London became the capital by default. During the whole medieval period, it wasn’t really the capital, it was sort of like this difficult city.
Ben Aaronovitch explains further about London during a discussion with fellow authors China Mieville, Kate Griffin and Suzanne McLeod. (Published in SFX magazine, issue #225, September 2012.)