Roland Perry wrote:

Ilford & Romford are nominally Essex for Post Code purposes and most
people assume they are in Essex

Do they really? Having spent many years living in Brentwood on and off
over the last few decades it (Brentwood) is quite well understood by
people who don't live there as the "First town in Essex" - looking out -
and the "Last town in Essex" - looking in.

Wasn't there a pattern that many Essex residents tended to see it as the
first suburb of London and many Londoners tended to see it as the first town
outside London?