There have been a considerable number of small changes to the Greater London boundary since its creation in 1965. The most significant of these were the 1969 transfers of Knockholt to Kent and Farleigh to Surrey and a series of minor adjustments during the 1990s which realigned the boundary to the M25 motorway in some places.

Date	Legislation	Effect
1 April 1965	London Government Act 1963	Greater London created from the County of London, most of Middlesex and parts of Essex, Kent, Surrey and Hertfordshire
1 April 1969	The Greater London, Kent and Surrey Order, 1968	Changes to the Bromley/Croydon/Kent/Surrey boundary: Transfer of Knockholt to Kent and Farleigh to Surrey
1 April 1970	The Greater London and Surrey Order, 1970	Changes to the Richmond-upon-Thames/Surrey boundary
1 April 1993	The Greater London and Kent (County Boundaries) Order 1992	Changes to the Bexley/Kent boundary
1 April 1993	The Greater London and Hertfordshire (County Boundaries) Order 1992	Changes to the Barnet/Harrow/Hertfordshire boundary
1 April 1994	The Heathrow Airport (County and London Borough Boundaries) Order 1993	Changes to the Hillingdon/Hounslow/Surrey/Buckinghamshire boundary: some alignment to the M25 motorway and Heathrow Airport brought entirely within Greater London †
1 April 1994	The Greater London and Surrey (County and London Borough Boundaries) Order 1993	Changes to the Croydon/Surrey boundary †
1 April 1994	The Greater London and Surrey (County and London Borough Boundaries) (No. 2) Order 1993	Changes to the Richmond/Surrey boundary †
1 April 1994	The Greater London and Surrey (County and London Borough Boundaries) (No. 3) Order 1993	Changes to the Croydon/Sutton/Surrey boundaries
1 April 1994	The Greater London and Surrey (County and London Borough Boundaries) (No. 4) Order 1993	Changes to the Hounslow/Surrey boundary
1 April 1994	The Greater London, Kent and Surrey (County Boundaries) Order 1993	Changes to the Bromley/Kent/Surrey boundary: Southern tip of Bromley at Tatsfield to Surrey †
1 April 1994	The Essex, Greater London and Hertfordshire (County and London Borough Boundaries) Order 1993	Changes to the Enfield/Hertfordshire boundary: some alignment to the M25 motorway
1 April 1994	The Essex and Greater London (County and London Borough Boundaries) (No.2) Order 1993	Changes to the Havering/Essex boundary: some alignment to the M25 motorway and transfer of part of Great Warley from Greater London †
1 April 1995	The Berkshire, Buckinghamshire and Surrey (County Boundaries) Order 1994	Changes to the Surrey/Buckinghamshire/Berkshire boundary give Greater London and Berkshire a new common boundary
1 April 1995	The Essex and Greater London (County Boundaries) Order 1993	Changes to the Redbridge/Essex boundary: Transfer of area around Grange Hill tube station to Greater London
1 April 1995	The Greater London and Surrey (County and London Borough Boundaries) Order 1994	Changes to the Kingston/Sutton/Surrey boundary †(Some changes to the Metropolitan Police District were later repealed)

† = also altered the boundaries of the Metropolitan Police District

Proposed changes

In 2004, following a poll, a move was mooted by the London Assembly to entirely align the Greater London boundary to the M25 motorway. The Mayor of London suggested in 2005 that Dartford, Thurrock and Watford could be given the opportunity to vote on inclusion in Greater London in local referenda.

References

1. The Greater London, Kent and Surrey Order, 1968
2. Elcock, H, Local Government, (1994)
3. Office of Public Sector Information - The Greater London and Kent (County Boundaries) Order 1992. Retrieved on 23 February 2008.
4. Office of Public Sector Information - The Heathrow Airport (County and London Borough Boundaries) Order 1993. Retrieved on 23 February 2008.
5. Office of Public Sector Information - The Greater London and Surrey (County and London Borough Boundaries) Order 1993. Retrieved on 23 February 2008.
6. Office of Public Sector Information - The Greater London and Surrey (County and London Borough Boundaries) (No. 2) Order 1993. Retrieved on 23 February 2008.
7. Office of Public Sector Information - The Greater London and Surrey (County and London Borough Boundaries) (No. 3) Order 1993. Retrieved on 23 February 2008.
8. Office of Public Sector Information - The Greater London and Surrey (County and London Borough Boundaries) (No. 4) Order 1993. Retrieved on 23 February 2008.
9. Office of Public Sector Information - The Greater London, Kent and Surrey (County Boundaries) Order 1993. Retrieved on 23 February 2008.
10. Office of Public Sector Information - The Essex, Greater London and Hertfordshire (County and London Borough Boundaries) Order 1993. Retrieved on 23 February 2008.
11. Office of Public Sector Information - The Essex and Greater London (County and London Borough Boundaries) (No.2) Order 1993. Retrieved on 23 February 2008.
12. Office of Public Sector Information - The Berkshire, Buckinghamshire and Surrey (County Boundaries) Order 1994. Retrieved on 23 February 2008.
13. Office of Public Sector Information - The Essex and Greater London (County Boundaries) Order 1993. Retrieved on 23 February 2008.
14. Office of Public Sector Information - The Greater London and Surrey (County and London Borough Boundaries) Order 1994. Retrieved on 23 February 2008.
15. Office of Public Sector Information - The Greater London and Surrey (County and London Borough Boundaries) (Variation) Order 1995. Retrieved on 23 February 2008.
16. London Assembly - Poll says M25 is London's "natural boundary". 2 March 2004. Retrieved on 23 February 2008.