Rising water levels cut off the Isle of Man from the surrounding islands around 8000 BCE.
Evidence suggests that colonisation of the island took place by sea some time before 6500 BCE. The first residents lived in small huts, hunting, fishing and gathering their food. They used small tools made of flint or bone, examples of which have been found near the coast. Representatives of these artefacts are kept at the Manx Museum.
At this time world population was essentially stable at around 5 million people, living mostly scattered across the globe in small hunter-gatherer bands. In the agricultural communities of the Middle East, the cow was domesticated and use of pottery became common, spreading to Europe and South Asia, and the first metal (gold and copper) ornaments were made.
The Neolithic Period marked the coming of knowledge of farming, better stone tools and pottery. It was during this period that megalithic monuments began to appear around the Island. Examples from this period can be found at Cashtal yn Ard near Maughold, King Orry’s Grave at Laxey, Meayll Circle near Cregneash and Ballaharra Stones at St John’s. This was not the only Neolithic culture, there were also the local Ronaldsway and Bann cultures.
During the Bronze Age, the large communal tombs of the megalith builders were replaced with smaller burial mounds. Bodies were put in stone-lined graves along with ornamental containers. The Bronze Age burial mounds created long-lasting markers around the countryside.
The Iron Age marked the beginning of Celtic cultural influence. Large hill forts appeared on hill summits, and smaller promontory forts along the coastal cliffs, while large timber-framed roundhouses were built. It is likely that the first Celtic tribes to inhabit the island were of the Brythonic variety. Around the 5th century AD, cultural influence from Ireland and migration, precipitated a process of Gaelicisation, evidenced by Ogham inscriptions, giving rise to the Manx language, which remains closely related to Irish and Scottish Gaelic.
Viking settlement of the Isle of Man began at the end of the 8th century. The Vikings established Tynwald and introduced many land divisions that still exist.
(text is an extract from wiki; painting by Zdenek Burian, 1957)