When did the Old Norse language originate?
Old Norse
The Proto-Norse language developed into Old Norse by the 8th century, and Old Norse began to develop into the modern North Germanic languages in the mid- to late 14th century, ending the language phase known as Old Norse. These dates, however, are not absolute, since written Old Norse is found well into the 15th century.
Icelandic language
The language of the sagas is Old Icelandic, a western dialect of Old Norse. The Dano-Norwegian, then later Danish rule of Iceland from 1536 to 1918 had little effect on the evolution of Icelandic (in contrast to the Norwegian language), which remained in daily use among the general population. Though more archaic than the other living Germanic languages, Icelandic changed markedly in pronunciation from the 12th to the 16th century, especially in vowels (in particular, ', ', "", and "/").