Tom, the correspondent who sent me the Romani links posted earlier today, has a question to which I do not know the answer, and I am hoping some of my readers do:
Today the name of the Russian language in Russian is russkii, but the name of the country is Rossiia. I realize that it was Peter the Great who changed the name of his realm from Muscovy (Moskovskoe Tsarstvo) to the Russian Empire (Rossiiskaia Imperia) in 1721. In doing so he fell on the Greek translation of the Slavic name Rus, that is, Rosia. In line with Peter’s choice, Lomonosov wrote about the Russian language as rossiiski, not russkii. But at the turn of the 19th century, the latter form had almost completely replaced the former. (The Latin translation of Rus was Ruthenia, which was preferred to the Greek version in Catholic and Protestant states west of Russia.)
I wonder why it happened and when exactly some official decision was taken to this effect.
The only inexact and vague hypothesis on the change I have drawn from books by the French Slavicist Danie Beavouis. Between 1772 and 1795, Austria, Prussia and Russia partitioned Poland-Lithuania. Russia got the entire Grand Duchy of Lithuania, whose law was based on the 16th-century Lithuanian Statute. The statute was composed in Cyrillic-based Ruthenian (ruski), which was the official language in the Duchy then. Ruthenian was based on the local Slavic dialects of the Orthodox population, who dubbed themselves ruski (Ruthenian), an adjective derived from the name of the medieval polity of Rus. This written vernacular of Ruthenian came in two varieties shaped by the two ducal chanceries in Vilnius and Kyiv. In turn, Ruthenian influenced the development of the still heavily Church Slavonicized Muscovian chancery language, before the latter spawned Russian as we know it.