Facts:

The origin of the name Oslo, initially spelled “Áslo” and later “Óslo”, is derived from Old Norse.

Old Norse is a North Germanic language that was spoken by inhabitants of Scandinavia and inhabitants of their overseas settlements during the Viking Age, until about 1300.

Gradually, Old Norse splintered into the modern North Germanic languages: Icelandic, Faroese, Norwegian (nynorsk), Norwegian (bokmål), Danish and Swedish.