Several species of humans have intermittently occupied Great Britain for almost a million years. The earliest evidence of human occupation around 900,000 years ago is at Happisburgh on the Norfolk coast, with stone tools and now destroyed footprints possibly made by Homo antecessor or Homo erectus. The oldest human fossils, around 480,000 years old, are of "Boxgrove Man" (possibly Homo heidelbergensis) from the Boxgrove site in Sussex. Until that time, Britain had been permanently connected to the Continent by a chalk ridge between South East England and northern France called the Weald–Artois Anticline, but during the Anglian Glaciation around 425,000 years ago a megaflood broke through the ridge, and Britain became increasingly isolated from continental Europe, until fully becoming an island around 130,000 years ago.
During the Lower Palaeolithic and Middle Palaeolithic, Britain was primarily inhabited by humans during warm interglacial periods, when Britain exhibited a temperate climate similar to modern times, alongside animals such as the straight-tusked elephant, lion (Panthera fossilis), cave hyenas, and Stephanorhinus rhinoceroses. Fossils of very early Neanderthals dating to around 400,000 years ago have been found at the Swanscombe site in Kent, and of classic Neanderthals about 225,000 years old at Pontnewydd in Wales. Britain was unoccupied by humans between 180,000 and 60,000 years ago, when Neanderthals returned. By 40,000 years ago they had become extinct and modern humans had reached Britain. But even their occupations were brief and intermittent due to a climate which swung between low temperatures with a tundra habitat and severe ice ages which made Britain uninhabitable for long periods. The last of these, the Younger Dryas, ended around 11,700 years ago, and since then Britain has been continuously occupied.
Traditionally it was claimed by academics that a post-glacial land bridge existed between Britain and Ireland; however, this conjecture began to be refuted by a consensus within the academic community starting in 1983, and since 2006 the idea of a land bridge has been disproven based upon conclusive marine geological evidence. It is now concluded that an ice bridge existed between Britain and Ireland up until 16,000 years ago, but this had melted by around 14,000 years ago. Britain was at this time still joined to the Continent by a land bridge known as Doggerland, but due to rising sea levels this causeway of dry land would have become a series of estuaries, inlets and islands by 7000 BC, and by 6200 BC, it would have become completely submerged.
Located at the fringes of Europe, Britain received European technological and cultural developments much later than Southern Europe and the Mediterranean region did during prehistory. By around 4000 BC, the island was populated by people with a Neolithic culture. This Neolithic population, like other European Neolithic farmers, drew the majority of their ancestry from the earliest farming communities in Anatolia, indicating that a major migration accompanied farming. The beginning of the Bronze Age and the Bell Beaker culture was marked by an even greater population turnover, this time displacing more than 90% of Britain's neolithic ancestry in the process. This is documented by studies of ancient DNA which demonstrate that the immigrants had large amounts of Bronze-Age Eurasian Steppe ancestry, associated with the spread of Indo-European languages and the Yamnaya culture.
No written language of the pre-Roman inhabitants of Britain is known; therefore, the history, culture and way of life of pre-Roman Britain are known mainly through archaeological finds. Archaeological evidence demonstrates that ancient Britons were involved in extensive maritime trade and cultural links with the rest of Europe from the Neolithic onwards, especially by exporting tin that was in abundant supply. Although the main evidence for the period is archaeological, available genetic evidence is increasing, and views of British prehistory are evolving accordingly. Julius Caesar's first invasion of Britain in 55 BC is regarded as the start of recorded protohistory although some historical information is available from before then.The fourth-century BC account by Pytheas has not survived, and only brief pieces of it are known from other writers.
Stone Age Palaeolithic
Palaeolithic (Old Stone Age) Britain is the period of the earliest known occupation of Britain by humans. The oldest known occupations of the island date to the end of the early Pleistocene, around 900,000 years ago. During the Palaeolithic, Britain was repeatedly colonised by archaic humans during temperate interglacial periods, before retreating during the harsh cold glacial periods. This process of colonisation and retreat is thought to have occurred at least 9 separate times. Habitation was intermittent, and even during periods of occupation may have reproduced below replacement level and needed immigration from elsewhere to maintain numbers. According to Paul Pettitt and Mark White: The British Lower Palaeolithic (and equally that of much of northern Europe) is thus a long record of abandonment and colonisation, and a very short record of residency. The sad but inevitable conclusion of this must be that Britain has little role to play in any understanding of long-term human evolution and its cultural history is largely a broken record dependent on external introductions and insular developments that ultimately lead nowhere. Britain, therefore, was an island of the living dead. Prior to around 130,000 years ago Britain was permanently a peninsula of mainland Europe, connected by chalk and clay rocks running across to northern France, allowing hominins to freely disperse into Britain. From around 500,000 years ago this land bridge began to erode, which was complete by around 130,000 years ago, resulting in Britain being an island during the Last Interglacial (130-115,000 years ago) and most the Holocene (from around 9,000 years ago), though it reconnected to Europe during Last Glacial Period (115,000-11,700 years ago) and remained connected into the early Holocene via Doggerland.
Lower Palaeolithic
Earliest occupations
There is evidence from animal bones and flint tools found in coastal deposits near Happisburgh in Norfolk that early humans were present in Britain over 800,000 years ago. Paleomagnetic analysis shows that the sediments in which the stone tools were found have a reversed polarity which means they are over 780,000 years old, prior to the Brunhes–Matuyama reversal.Britain One Million Years of the Human Story by Rob Dinnis & Chris Stringer published by the Natural History Museum, London 2013. Reprinted with updates 2023. ISBN 978 0 565 09337 2 The evidence is that the early humans were there towards the end of an interglacial during that date range. There are two candidate interglacials - one between 970,000 and 935,000 years ago and the second from 865,000 and 815,000 years ago. Numerous footprints of equivalent age to the tools were found on the beach at Happisburgh in 2013 of a mixed group of adult males, females and children. No human fossils have been found at Happisburgh. It has been tentatively proposed that Homo antecessor is the most likely candidate species of ancient human as there are remains of roughly the same age at Gran Dolina at Atapuerca, northern Spain, though a later 2020 study noted that the footprints were similar to those made by Homo erectus.
Summer temperatures at Happisburgh were an average of and average winter temperatures were slightly colder than present day temperatures, around freezing point or just below. Conditions were comparable to present-day southern Scandinavia. During this time, the area was inhabited by species such as the temperate adapted mammoth Mammuthus meridionalis, the equine Equus suessenbornensis and the giant moose ancestor Cervalces latifrons.
Chronologically, the next evidence of human occupation is at Pakefield on the outskirts of Lowestoft in Suffolk south of Happisburgh, dating to an interglacial period around 700,000 years ago (Marine Isotope Stages 19-17), with lithic artefacts showing a core and flake industry. This site is in the vicinity of the lower Bytham river, and not the Thames which had now moved further south. Pakefield had mild winters and warm summers with average July temperatures of between . There were wet winters and drier summers. Animal bones found in the area include those of animals such as the steppe mammoth (Mammuthus trogontherii), the extinct hippo Hippopotamus antiquus, the rhinoceros Stephanorhinus hundsheimensis, the giant deer Praemegaceros dawkinsi, the deer Megaloceros savini, the bison Bison cf. schoetensacki, the enormous lion Panthera fossilis, Crocuta hyenas related to the living spotted hyena (Crocuta crocuta), grey wolf (Canis lupus) and the sabertooth cat Homotherium. Flakes from Fakenham Magna in Suffolk may also represent evidence of an occupation of Britain during MIS 19.
Acheulean
The oldest possible Acheulean industry site utilizing handaxes in Britain is Fordwich Pit near Canterbury, Kent, with a 2025 study suggesting that the earliest occupation at the site to dates MIS 17-16, around 712–621,000 years ago, though other authors have expressed skepticism due to the handaxes being recovered without adequate documentation, and suggested that the earliest handaxes at the site may date to MIS 15 instead, consistent with other British sites. Archaic humans are suggested to have been present in Britain during MIS 15, around 620-560,000 years ago, as evidenced by handaxes found in several sites on the former Bytham River in eastern England such as Brandon Fields and Maidscross Hill, as well as elsewhere in England. The oldest skeletal remains of humans in Britain are of "Boxgrove Man", comprising a tibia and two incisor teeth from the lower jaw, suggested to represent remains of Homo heidelbergensis, collected from the Boxgrove site in West Sussex, dating to around 480,000 years ago at the end of Marine Isotope Stage 13. This site has also provided abundant evidence of human activity, including lithic artefacts of an Acheulean industry with highly refined ovate handaxes, as well as an animal butchery, including of rhinoceroses (Stephanorhinus hundsheimensis), deer, bear (Ursus deiningeri) and horses, that occurred during a warm interglacial in coastal, grassland and forest environments. Boxgrove-type ovate handaxes are also found at other sites in Britain of MIS 13 age, as distant as East Anglia, and show a great increase in knapping skill over the much more crude handaxes found in Fordwich Pit and MIS 15 deposits.
The extreme cold of the following Anglian Stage (Marine Isotope Stage 12) was previously thought to have driven humans out of Britain altogether. The discovery of sharp, unworn stone tools sandwiched between two Anglian sediment layers at Fordwich Pit in Kent, however, suggests at least some human populations visited Britain during this ice age, perhaps during a relatively warm interstadial period although probably not when glaciers reached their southern limit north of Old Park.