[dghf]

> In fact, until 1889, "London" referred to the City.

Here's a Post Office map of London from 1857: https://mapco.net/kelly1857/kelly.htm

As you can see, it covers a much larger area than just the City.

19th century writers -- e.g. Austen, Trollope, Doyle -- use "London" to mean the metropolis as a whole, not just the City.

And Apsley House, built in the 1770s, was for years popularly known as "No. 1, London", because it was the first house you passed after going through the toll-gates at Knightsbridge (at the western edge of Westminster).