Scottish Gaelic developed as an independent language after the 12th century.
Achomi is close to Persian in some aspects but it is an independent language.
It doesn't pay much attention to the past, even its own, possibly because it wasn't acknowledged to be an independent language until the 20th century.
New Persian developed from the 8th century on as an independent literary language.
However, they did not consider Kodava an independent language.
Part of this nationalist movement was directed towards the development of an independent Norwegian language.
Konkani is an independent language and not a dialect of Marathi.
However, the remains of their older, independent language still survive in bits and pieces.
Among his famous teachings were that Catalan did not exist as an independent language prior to 1326.
Punjabi emerged as an independent language in the 12th century.