A former inland county of England, partly absorbed into the erstwhile County of London in 1889; finally abolished in 1965 and absorbed mainly into Greater London, the south-west corner of the county becoming part of Surrey.
"The historic county of Middlesex was largely merged into Greater London when it was abolished in 1965."
The name comes from the Old English Middelseaxan, meaning "Middle Saxons," referring to both the county and its inhabitants. It was originally used as a collective term for the people living in that region before becoming specifically associated with the place itself.