Here's a map of the counties of Britain.
And here's
a link to a definition of the South-East of England, which says: "South East England is the most populous of the nine
official regions of England ... It consists of Berkshire, Buckinghamshire, East Sussex, Hampshire, the Isle of Wight, Kent, Oxfordshire,
Surrey and West Sussex."
(Sorry, but I had to do something to stop myself from banging my head on the wall.
)