High Quality Content by WIKIPEDIA articles! In the 9th century, Old Norse began to diverge into Old West Norse (Norway and Iceland) and Old East Norse (Sweden and Denmark). In the 12th century, the dialects of Denmark and Sweden began to diverge, becoming Old Danish and Old Swedish in the 13th century. All were heavily influenced by Middle Low German during the medieval period. Though stages of language development are never as sharply delimited as implied here, and should not be taken too literally, the system of subdivisions used in this article is the most commonly used by Swedish linguists and is used for the sake of practicality.