"1:10,000 map SE82SE, 1971". National Library of Scotland. Ordnance Survey. Retrieved 24 March 2024. Note the distinction in the key and on the map between the boundaries of geographical counties and the administrative counties.
Because the City of London has a Commission of Lieutenancy rather than a single lord-lieutenant, it is treated as a county for some purposes of the Lieutenancy Act. (Schedule 1 paragraph 4)