"John Rowland" wrote in message
...

I think that Brighton and the two Sussexes shared a common
police force, too (but I might be wrong on that one).

Yes, they do. Council tax bills for Brighton & Hove residents include a
separately itemised amount for funding Sussex Police.

When did East Sussex, West Sussex and Brighton exist as three separate
counties?

Now. East Sussex CC, West Sussex CC, Brighton & Hove UA (AFAIAA East Sussex
CC no longer has *any* administrative powers in Brighton and Hove).

D A Stocks