In passing the Irish differentiated between the Danes and the Norwegians. The Danes were called "Dubh-Gall" and the Norwegians "Fionn-Gall." (Black Foreigners and Fair Foreigners). For a greater explanation see "The Story of the Irish Race", by Seumas MacManus. (Chapter 30; The Vikings in Ireland). Regarding the use of the word "mainland", I understand that the word was first used by Margaret Thatcher in order to give the impression that Ireland was nothing more than an extension of Britain.