"Meithei represents the language of the original settlers in Manipur, and Chin that of the southern migration. In these southern seats the language rapidly developed, partly by its own natural growth and partly owing to contact with the Burmese. The development of Meithei, the language of the Manipuris, has, on the other hand, been slow and independent. The Manipuris are mentioned in the Shan chronicles so early as A.D. 777, and probably owing to the fact that it has in later times developed into a literary language, their form of speech gives the impression of possessing a peculiarly archaic character. Although they have become thoroughly Hinduised, they have not adopted any Aryan tongue; Meithei is the official language of the State, which all other tribes have to use in dealing with their rulers."
January 1, 1970
https://en.wikiquote.org/wiki/Meitei_language