In summary the title, I want to learn more about where the Icelandic language started to become its own language separate from the Danish. From what I’ve done of my own online research is that it’s more close to old Norse than other Scandinavian languages with a few modernized ways of pronouncing and spelling certain words.
I’m wondering if anyone here knows a good timeline or great reading I can look into to learn more, if not at least find a good foothold to look into more.
Hello, sorry for the very late response.
If you wish to read a concise introduction for the history of the Icelandic Language, I'd strongly recommend to check Stefán Karlsson, the Icelandic Language, trans. Rory McTurk, London: Viking Society, 2004, at first (since it is free pdf file uploaded officially).
Other seminal articles in historical Scandinavian languages in English are to be found in the following two-volumes series, but it is very, very expensive: The Nordic Languages: An International Handbook of the History of the North Germanic Languages, ed. Oskar Bandle et al., 2 vols., Berlin: de Gruyter, 2002 (online ed. 2008).
+++
I want to learn more about where the Icelandic language started to become its own language separate from the Danish.
It was rather the Danish that had already diverged from the Old Norse brother languages (Old Icelandic/ Old Norwegian) enough by its annexation of Iceland into the Kalmar Union in the 14th century.
If specialists looks at non-normalized handwriting in the 14th century Icelanic manuscripts closely, they can also detect some traces of Norwegian style of spelling (Stéfan Karlsson 2004: 47f.), so even Old Icelandic and Old Norwegian also began to diverge each other though to a limited extent before the Black Death that trigger the latter's transition to the Middle Norwegian (mellomnorsk - see also my recent post in: How salient was the transition of the written language from Norwegian to Danish in post-reformation Norway?).