Dun na nGall, 'Fort of the Foreigners'?

Dú n na nGall, the Irish name for ' Donegal', translates as ' Fort of the Foreigners', but who were the foreigners in question. This book considers that they were Vikings and reviews the archaeological and documentary evidence for Vikings in Donegal and addresses the nature of Viking activity and possible settlement in the county. From Viking silver hoards found throughout Inishowen to a potential Viking-type dwelling at Portnablagh, the evidence for Vikings is strongest in the north and east of the county.