On 2016\01\22 12:30, aurora wrote:

Then in 1965 came the ultimate land grab. Newly created Greater
London stretched from Chessington to Enfield. Middlesex ceased to
exist as a county authority. Most of remaining Middlesex became
Greater London, with small enclaves transferring to Surrey.

Or Herts.

Incidentally, the county boundary between Potters Bar and Barnet used to
have Hertfordshire on the south side and now the same county boundary
has Hertfordshire on the north side. Could this be a unique occurrence
in the world? I wonder if the "Welcome to Hertfordshire" signs were just
turned around on the same pole.