A recent history of UK local government restructuring
As a result of attempts to introduce the most efficient system of local government for different areas, several major structural changes have been made since the 1960s.
In the early 1960s the UK was covered by two-tier administrations, based on counties and a mixture of sub-administrations including municipal boroughs, county boroughs, rural districts and urban districts. The Isles of Scilly in England had their own single-tier administration.
In 1965 a new structure was introduced to London whereby Greater London was formed from segments of the surrounding counties, with the boroughs being the lower tier of the system.
In 1974 a similar two-tier structure was introduced to the rest of England and Wales whereby revised (and in many cases larger) counties, also known as shire counties, provided the top tier of local government and non-metropolitan districts the lower tier.
In heavily urbanised areas, six of these counties were known as metropolitan counties, with the subdivisions called metropolitan districts. The Isles of Scilly retained their own set-up.
Scotland had the same structure introduced in 1975 except that the upper-tier units were known as regions.
Northern Ireland however had had its entire two-tier system replaced in 1973 by 26 single-tier district councils. In 2015, further reorganisation resulted in the establishment of 11 district councils to replace the 26 previous district councils.
Scotland and Wales had their two-tier systems replaced in 1996, in Scotland by a single-tier system of council areas and in Wales by a similar system of unitary authorities.
In 1986 in England, the Greater London Council and the six metropolitan counties were abolished, leaving the boroughs and districts to operate as single-tier units, although the abolished larger areas are still recognised for some purposes such as statistical presentation.
Then, in the 1990s and again between 2009 and 2021, it was decided that the two-tier system was not the most efficient local government structure for some areas in England and the situation became rather more complex, as described below:
Local government reorganisation in England
Between 1995 and 1998, parliament approved a phased local government reorganisation in 25 counties, resulting in the creation of 46 new Unitary Authorities (UAs).
Between 2009 and 2021, there was further local government reorganisation, and parliament approved a further 14 new UAs.
In 1995, one UA was created. The two districts of the Isle of Wight were merged and the county became a UA.
In 1996, 13 UAs were created. The counties of Avon, Cleveland and Humberside were all abolished and each county split into four UAs. York UA was created by being split from the county of North Yorkshire.
In 1997, 11 UAs were created. A number of former districts comprising large towns and cities were detached from their counties and became UAs: Bournemouth, Brighton and Hove, Darlington, Derby, Leicester, Luton, Milton Keynes, Poole, Portsmouth, and Southampton. The historic county of Rutland was detached from Leicestershire and became a UA.
In 1998, 21 UAs were created, many reflecting city areas detached from their counties. The county of Hereford and Worcester was divided into the county of Worcestershire, and Herefordshire UA. The county of Berkshire was abolished and split into six UAs.
In 2009, nine UAs were created. These involved the county of Bedfordshire being abolished and split into two UAs, and the county of Cheshire being abolished and split into two UAs. In addition, five complete counties were abolished and created as five separate UAs, Cornwall, County Durham, Northumberland, Shropshire and Wiltshire.
In 2019, two UAs were created. Dorset county was abolished. The separate UAs of Bournemouth and Poole, created in 1997 were merged with Christchurch to create Bournemouth, Christchurch and Poole UA. The remainder of Dorset county became Dorset UA.
In 2020, one UA was created. The four districts in Buckinghamshire were merged and the county became a UA.
In 2021, two UAs were created. The county of Northamptonshire was abolished and divided into two UAs, North Northamptonshire and West Northamptonshire.
In 2023, four UAs were created. The counties of Cumbria, North Yorkshire and Somerset were abolished and divided into four UAs, Cumberland, Westmorland and Furness, North Yorkshire and Somerset.
The current structure consists of 21 shire counties split into 164 districts, plus 63 UAs.
Only nine pre-1995 shire counties have been unaffected by these changes (Gloucestershire, Hertfordshire, Lincolnshire, Norfolk, Oxfordshire, Suffolk, Surrey, Warwickshire and West Sussex).
Metropolitan districts were not included in the local government reorganisation and have retained their post-1986 status, and in 2000 the London boroughs became subject to the London-wide authority.