Merseyside spans 249 square miles (645 km2) of land which border Lancashire (to the north-east), Greater Manchester (to the east), Cheshire (to the south and south-east) and the Irish Sea to the west. North Wales is across the Dee Estuary. There is a mix of high density urban areas, suburbs, semi-rural and rural locations in Merseyside, but overwhelmingly the land use is urban. It has a focused central business district, formed by Liverpool City Centre, but Merseyside is also a polycentric county with five metropolitan districts, each of which has at least one major town centre and outlying suburbs. The Liverpool Urban Area is the fifth most populous conurbation in England, and dominates the geographic centre of the county, while the smaller Birkenhead Urban Area dominates the Wirral Peninsula in the south.
For the 12 years following 1974 the county had a two-tier system of local government; district councils shared power with the Merseyside County Council. The county council was abolished in 1986, and so its districts (the metropolitan boroughs) are now effectively unitary authority areas. However, the metropolitan county continues to exist in law and as a geographic frame of reference, and several county-wide services are co-ordinated by authorities and joint-boards, such as Merseytravel (for public transport), Merseyside Fire and Rescue Service and the Merseyside Police (for law-enforcement); as a ceremonial county, Merseyside has a Lord Lieutenant and a High Sheriff. The boroughs of Merseyside are joined by the neighbouring borough of Halton in Cheshire to form the Liverpool City Region, which is a local enterprise partnership and combined authority area.
Merseyside is an amalgamation of 22 former local government districts from the former administrative counties of Lancashire, Cheshire and six autonomous county boroughs centred on Birkenhead, Bootle, Liverpool, Southport, St. Helens, and Wallasey.
Merseyside was designated as a "Special Review" area in the Local Government Act 1958, and the Local Government Commission for England started a review of this area in 1962, based around the core county boroughs of Liverpool/Bootle/Birkenhead/Wallasey. Further areas, including Widnes and Runcorn, were added to the Special Review Area by Order in 1965. Draft proposals were published in 1965, but the commission never completed its final proposals as it was abolished in 1966.
Instead, a Royal Commission was set up to review English local government entirely, and its report (known as the Redcliffe-Maud Report) proposed a much wider Merseyside metropolitan area covering southwest Lancashire and northwest Cheshire, extending as far south as Chester and as far north as the River Ribble. This would have included four districts: Southport/Crosby, Liverpool/Bootle, St. Helens/Widnes and Wirral/Chester. In 1970 the Merseyside Passenger Transport Executive (which operates today under the Merseytravel brand) was set up, covering Liverpool, Sefton, Wirral and Knowsley, but excluding Southport and St. Helens.