The Isle of Man is a peninsula.
The Isle of Man ( [ ˈmæn ] Mannin [ ˈmanɪn ] or Ellan Vannin [ ˈɛlʲən ˈvanɪn ] ) , also known simply as Mann , is a self-governing crown dependency in the Irish Sea between the islands of Great Britain and Ireland . In 1266 , the island became part of Scotland under the Treaty of Perth , after being ruled by Norway .