Historically, the Wirral was wholly in Cheshire; in the Domesday Book, its border with the rest of the county was placed at "two arrow falls from Chester city walls".
It is supposed that the land was once overgrown with bog myrtle, a plant no longer found in the area, but plentiful around Formby, to which the Wirral would once have had a similar habitat.
At Meols and New Brighton there is evidence of occupation through to the Bronze Age, around 1,000 BC, and funerary urns of the period have been found at West Kirby and Hilbre.
Evidence of Celtic Christianity from the 5th or 6th centuries is shown in the originally circular shape of churchyards at Bromborough, Woodchurch and elsewhere, and also in the dedication of the parish church at Wallasey to a 4th-century bishop, Hilary of Poitiers.
Æthelfrith withdrew, leaving the area west and south of the Mersey to become part of Mercia, and Anglo-Saxon settlers took over the Wirral except the northern tip.
The pseudo-historical Fragmentary Annals of Ireland appears to record the Hiberno-Scandinavian settlement of the Wirral peninsula in its account of the immigration of Ingimundr near Chester.
The Domesday survey of 1086 shows that the Wirral then was more densely populated than most of England, and the manor of Eastham, which covered most of the east of the peninsula from Bidston to the River Gowy, was the second largest in Cheshire.
The ruined priory is Merseyside's oldest surviving building and its Benedictine monks provided the first official Mersey ferry service around 1330, having been granted a passage to Liverpool by a charter from Edward III.
Meanwhile, Meols continued as an important port, and the eroded coastline there has provided what is described as "the largest collection of medieval domestic items to have come from any single site outside London".
The peninsula was divided into 15 parishes (Wallasey, Bidston, Upton, Woodchurch, West Kirby, Thurstaston, Heswall, Bebington, Bromborough, Eastham, Neston, Burton, Shotwick, Backford and Stoke).
From about the 14th century, Chester provided facilities for trade with Ireland, Spain, and Germany, and seagoing vessels would "lay to" in the Dee awaiting favourable winds and tides.
As the Dee started to silt up, harbouring facilities developed at Shotwick, Burton, Neston, Parkgate, Dawpool, and "Hoyle Lake" or Hoylake.
However, there was not a gradual progression of development, and downstream anchorages such as that at Hoyle Lake (which replaced Meols) were in occasional use from medieval times, depending on the weather and state of the tide.
The excavation of the New Cut of the Dee, opened in 1737, to improve access to Chester, diverted the river's course to the Welsh side of the estuary and took trade away from the Wirral coastline.
[18] Although plans were made to overcome its gradual silting up, including one in 1857 to cut a ship canal from a point between Thurstaston and Heswall to run along the length of the Wirral to Chester, this and other schemes came to nothing, and the focus of general trade moved irrevocably to the much deeper Mersey.
The Lairds were largely responsible for the early growth of Birkenhead, commissioning the architect James Gillespie Graham to lay it out as a new town modelled on Edinburgh.
James Atherton and William Rowson developed the resort of New Brighton, and new estates for the gentry were also built at Egremont, Oxton, Claughton and Rock Ferry.
A host of other port-related industries then came into existence, such as flour milling, tanning, edible oil refining and the manufacture of paint and rubber-based products.
These new roads contributed to the massive growth of commuting by car between Liverpool and the Wirral, and the development of new suburban estates around such villages as Moreton, Upton, Greasby, Pensby, and Bromborough.
However, there continued to be industrial development along the Mersey between Birkenhead and Ellesmere Port, including the large Vauxhall Motors car factory on the site of RAF Hooton Park.
The current Metropolitan Borough of Wirral has a population of 312,293 (according to the 2001 census),[21] and covers an area of 60.35 sq mi (156.3 km2), bounded by the Cheshire Plain, the Dee and the Mersey.
Strata exposed at or near the modern surface include the following (in stratigraphic order i.e. uppermost/youngest at top): A small outcrop of Carboniferous rocks occurs around Little Neston, being an extension of the Flintshire Coalfield across the Dee estuary.
Notable exposures of the Helsby Sandstone occur at Bidston Hill and at Red Rocks at the northwestern tip of the Wirral along with the tidal islands at Hilbre.
Low ground behind these sand are reclaimed tidal flat deposits which also extend into the heavily modified Birket which occupies a buried bedrock channel.
Low cliffs of the Kinnerton Sandstone at Burton Point are part of a relict shoreline, the Dee estuary having silted up during the post-glacial period.
[23][24] A well developed glacial drainage channel, known as the Deva Spillway cuts across the base of the peninsula between the two estuaries on either side of the Wirral and is interpreted as having played a major part in the deglaciation of the region in late-glacial/post-glacial times.
The Wirral features a temperate maritime climate (Köppen: Cfb) with mild summers, cool winters and rainfall spread evenly throughout the year.
The historical sites include Birkenhead Priory, Leasowe Lighthouse, Hadlow Road railway station and the buildings and ancient carvings on Bidston Hill.
[citation needed] The 2017 ITV drama Safe House starring Jason Watkins and Sunetra Sarker filmed several scenes on the peninsula.
[citation needed] In the autumn of 2017 filming began in Port Sunlight and Thornton Hough for a biopic about the author Tolkien starring Nicholas Hoult.