Middlesex is a historic county of England, north of the Thames and immediately west and north of the City of London. It covered about 232 square miles (601 km2), which made it the second smallest historic county after Rutland, and it was abolished as an administrative unit on 1 April 1965.
Almost all of it is now inside Greater London. Two outlying pieces went elsewhere: Potters Bar to Hertfordshire, and Staines, Sunbury-on-Thames and Shepperton to Surrey. The name survives in addresses, in Middlesex County Cricket Club and in Middlesex University.
| Country | England, United Kingdom |
|---|---|
| Status | Historic county; abolished as an administrative county in 1965 |
| Area | 232 sq mi (601 km2) |
| Name from | The Middle Saxons, “Middel Seaxe” |
| Traditional county town | Brentford |
| County council | Middlesex County Council, 1889 to 1965 |
| Successor areas | 9 London boroughs, plus Spelthorne (Surrey) and Potters Bar (Hertfordshire) |
| Population today | About 2.7 million in the area of the former administrative county |
| Postcode areas | EN, HA, N, NW, TW, UB, W |
Towns and Villages in Middlesex
Middlesex had no large towns for most of its history. Its market centres were small, and the county was farmland, market gardens and hay meadows supplying London. Almost all of the places below grew into London suburbs between 1900 and 1939, when the Metropolitan and District railways were extended west and north.
The list groups the county’s towns and villages by the authority that covers them now.
Barnet (part)
- Church End
- Colindale
- East Finchley
- Edgware
- Finchley
- Friern Barnet
- Golders Green
- Hendon
- Mill Hill
- North Finchley
- Whetstone
Brent
- Alperton
- Cricklewood
- Harlesden
- Kensal Green
- Kilburn
- Kingsbury
- Neasden
- Preston
- Queensbury
- Stonebridge
- Sudbury
- Wembley
- Willesden
Ealing
- Acton
- Ealing
- Greenford
- Hanwell
- Northolt
- Norwood Green
- Perivale
- Southall
- West Ealing
Enfield
- Bowes Park
- Bush Hill Park
- Edmonton
- Enfield Town
- Enfield Wash
- Forty Hill
- Palmers Green
- Ponders End
- Southgate
- Winchmore Hill
Haringey
- Crouch End
- Highgate
- Hornsey
- Muswell Hill
- Tottenham
- Wood Green
Harrow
- Harrow on the Hill
- Harrow Weald
- Hatch End
- Kenton
- North Harrow
- Pinner
- Rayners Lane
- South Harrow
- Stanmore
- Wealdstone
Hillingdon
- Cowley
- Eastcote
- Harefield
- Harlington
- Harmondsworth
- Hayes
- Hillingdon
- Ickenham
- Northwood
- Ruislip
- Sipson
- Uxbridge
- West Drayton
- Yeading
- Yiewsley
Hounslow
- Bedfont
- Brentford
- Chiswick
- Cranford
- Feltham
- Hanworth
- Heston
- Hounslow
- Isleworth
- Osterley
- Syon
Richmond upon Thames (part)
- Hampton
- Hampton Hill
- Hampton Wick
- Teddington
- Twickenham
- Whitton
Spelthorne, Surrey
- Ashford
- Charlton
- Halliford
- Laleham
- Littleton
- Shepperton
- Staines-upon-Thames
- Stanwell
- Sunbury-on-Thames
Hertsmere and Welwyn Hatfield, Hertfordshire
- Potters Bar
- South Mimms
Geography
Middlesex was defined by water on three sides. The Thames formed the whole southern boundary, from Staines to the edge of the City. The Lea marked the eastern border with Essex, and the Colne the western border with Buckinghamshire. Only the northern boundary, a low ridge running towards Hertfordshire, was drawn on land.
The ground is mostly London Clay under gravel terraces, flat in the south along the Thames and rising gently north-west. The highest ground is the ridge at Stanmore and Harrow Weald, at about 150 metres. Harrow on the Hill, with its church spire visible for miles, is the county’s landmark.
Smaller rivers cross it: the Brent, dammed to form the Welsh Harp reservoir; the Crane through Cranford and Twickenham; and the Pinn and the Yeading Brook in the west. Bushy Park and Hampton Court Park lie at the south-western corner.
Modern neighbours of the historic area are Hertfordshire to the north, Essex across the Lea, Buckinghamshire across the Colne and Surrey across the Thames. The whole area now falls within Greater London except for the Surrey and Hertfordshire fragments.
Demographics
Middlesex was thinly peopled outside London until the railways arrived. The administrative county held about 792,000 people in 1891, roughly 1.5 million by 1921 and more than 2.2 million by 1951, one of the fastest growth rates recorded for any English county.
The nine successor London boroughs held about 2.5 million residents at the 2021 census, with a further 100,000 in Spelthorne and around 22,000 in Potters Bar. Ealing, Barnet, Enfield and Hillingdon are each larger than most English counties’ county towns.
The area is now among the most ethnically diverse in Britain. Southall, Wembley and Hounslow have large Indian and Pakistani heritage populations, and Harrow has the highest share of Hindu residents of any local authority in England and Wales.
Economy and Local Life
Middlesex fed London. Market gardens around Isleworth, Heston and Hayes supplied vegetables, the Hounslow and Harmondsworth fields supplied hay for London’s horses, and Brentford was the main market town on the road west.
Industry came with the arterial roads in the 1920s and 1930s. Factories lined the Great West Road at Brentford and the A40 at Perivale and Greenford, producing everything from tyres to gramophone records. Several of the art deco factory buildings survive, including the former Hoover works on Western Avenue.
Aviation reshaped the south-west. Heathrow opened as a civil airport in 1946 on the market gardens of Heath Row hamlet, and it now dominates employment across Hillingdon, Hounslow and Spelthorne.
Sport keeps the county name in daily use. Middlesex County Cricket Club has played at Lord’s in St John’s Wood since 1877, and Twickenham has been the home of English rugby union since 1909.
History
The name records the Middle Saxons, a group settled between the East Saxons of Essex and the West Saxons of Wessex. Their territory was absorbed into the kingdom of Essex, and the shire of Middlesex was carved out of it in the ninth or tenth century.
The City of London became a county corporate in the twelfth century and its sheriffs also served Middlesex, so the county never had a sheriff of its own until 1889. The Tower Division in the east, later Tower Hamlets, had its own lieutenancy and considerable independence.
The Local Government Act 1888 removed the built-up south-east of the county to form the new County of London, taking about a third of the area and most of the population. Middlesex County Council was created for what was left and met in Westminster, in the Middlesex Guildhall built at Parliament Square in 1913. That building is now the Supreme Court of the United Kingdom.
The London Government Act 1963 abolished the county on 1 April 1965. Its territory formed nine of the new outer London boroughs, with Potters Bar going to Hertfordshire and the Staines and Sunbury area to Surrey. Middlesex remained in postal addresses until Royal Mail dropped postal counties from its requirements in 1996, and it is still written by many residents.
Getting There
The historic county is crossed by the M4, M25, M40, A40 Western Avenue, A4 Great West Road, A10 and A406 North Circular. The M25 cuts through its western edge near Staines and its northern edge near Potters Bar.
London Underground reaches almost all of it. The Metropolitan line runs to Uxbridge, Amersham and Watford, the Piccadilly to Heathrow and Cockfosters, the Central to West Ruislip, the Northern to Edgware and High Barnet, and the District to Richmond and Ealing Broadway. The Elizabeth line runs from Hayes and Harlington through West Ealing to central London.
National Rail serves Enfield, Southgate, Staines and Sunbury, and the Great Western Main Line runs west through Hanwell and Southall. Heathrow Airport sits inside the historic boundary, near the former hamlets of Heath Row, Sipson and Harmondsworth.
Frequently Asked Questions
Does Middlesex still exist?
Not as a local authority. It was abolished on 1 April 1965 and is now a historic county, kept alive in addresses, sport and institutions.
Which towns were in Middlesex?
Among others Uxbridge, Brentford, Enfield, Tottenham, Hornsey, Ealing, Harrow, Hounslow, Twickenham, Wembley, Hendon, Staines, Sunbury-on-Thames and Potters Bar.
What replaced Middlesex?
Nine London boroughs: Barnet in part, Brent, Ealing, Enfield, Haringey, Harrow, Hillingdon, Hounslow and part of Richmond upon Thames. Spelthorne went to Surrey and Potters Bar to Hertfordshire.
What was the county town of Middlesex?
Brentford is the traditional answer, as the place where county elections were held. County administration was actually run from Westminster, at the Middlesex Guildhall from 1913.
Which postcodes cover the old Middlesex?
EN, HA, N, NW, TW, UB and W. Royal Mail stopped requiring the county name in addresses in 1996.
Why is it called Middlesex?
From the Middle Saxons, the people settled between the East Saxons of Essex and the West Saxons of Wessex.