The Isle of Man became separated from Britain and Ireland by about 8000 BC. It appears that colonisation took place by sea sometime before 6500 BC. The island has been visited by various raiders and trading peoples over the years. After being settled by people from Ireland in the first millennium, the Isle of Man was converted to Christianity and then suffered raids by Vikings from Norway. After becoming subject to suzerainty to Norway as part of the Kingdom of Mann and the Isles, the Isle of Man later became a possession of the Scottish and then English crowns.