Old Norse Philology

Old Norse philology is the study of Old Norse language, literature, and culture. Old Norse was the language spoken and written in Medieval and Viking Scandinavia, as well the Norse colonies often referred to as the Viking diaspora. Old Norse is also the grandfather of the Scandinavian languages, including Icelandic and Faeroese. It is commonly divided into West and East Norse. West Norse encompasses Norway, Iceland, the Faeroe Islands and the Hebrides, while Denmark, Sweden and Gotland belonged to the East Norse language area.
They have a common ancestry in Proto-Scandinavian, which is the language of the oldest runic inscriptions, which in developed out of a Northern dialect of Proto-Germanic. 

Kilde:Wikimedia Commons
The Germanic languages around the North-Atlantic in the 10th century
Red: Old Norwegian and Old Icelandic (West Norse, North Germanic)
Orange: Runic Danish and Runic Swedish (East Norse, North Germanic)
Purple: Old Gutnish (East Norse, North Germanic)
Yellow: Old English (West Germanic)
Green: Various West Germanic languages (such as Frankish and Old High German)