Claim: The Isle of Man was once under the sovereignty of Norway.

The Isle of Man -LRB- -LSB- ˈmæn -RSB- Mannin -LSB- ˈmanɪn -RSB- or Ellan Vannin -LSB- ˈɛlʲən ˈvanɪn -RSB- -RRB- , also known simply as Mann , is a self-governing crown dependency in the Irish Sea between the islands of Great Britain and Ireland . The head of state is Queen Elizabeth II , who holds the title of Lord of Mann . The Lord of Mann is represented by a Lieutenant Governor . Foreign relations and defence are the responsibility of the British Government .   The island has been inhabited since before 6500 BC . Gaelic cultural influence began in the 5th century and the Manx language , a branch of the Gaelic languages , emerged . In 627 , Edwin of Northumbria conquered the Isle of Man along with most of Mercia . In the 9th century , Norsemen established the Kingdom of the Isles . Magnus III , King of Norway , was also known as King of Mann and the Isles between 1099 and 1103 .   In 1266 , the island became part of Scotland under the Treaty of Perth , after being ruled by Norway . After a period of alternating rule by the kings of Scotland and England , the island came under the feudal lordship of the English Crown in 1399 . The lordship revested into the British Crown in 1765 , but the island never became part of the Kingdom of Great Britain or its successor the United Kingdom : it retained its status as an internally self-governing Crown dependency .