In article ,
Martin Underwood writes
You'd think that it would make sense for the boundaries between one
"county" and another to be moved from time to time to take account of
any urban sprawl of a city on the boundary, so as always to avoid
splitting that city. The conurbation of Reading is split between
Reading, West Berkshire and Wokingham, when it would be much better for
the boundary to be moved so it runs through sparsely-populated areas
between Reading and the surrounding villages. Likewise for London -
though where you (literally!) draw the line between London and its
surroundings is a more difficult one!

This happened in Reading about a century ago. The Berks/Oxon boundary
used to be the Thames, then Caversham - the Reading suburb north of the
Thames - was moved into Berks, and into Reading.
--
Thoss