This article examines the process of formation of the translation service in the Moscow state during the late XV-XVI centuries. The repertoire of Eastern languages available to Moscow translation specialists is analyzed. The author came to the conclusion that among the eastern languages, the main language of negotiations and correspondence was the languages of the Turkic group, and the use of Farsi at this time is questionable. The original form of international communication in the Moscow state was oral, and written communication was considered less honorable and performed an official, auxiliary function. Gradually, at the turn of the XV-XVI, oral communication gave way to the exchange of embassy certificates. After the dispute between the rulers about the language of diplomatic correspondence in 1563, recorded in the Russian-Crimean diplomatic correspondence, the parties returned to the usual practice of exchanging messages and the Crimean Tatar language retained its role as the language of diplomatic communication. Three groups of specialists engaged in cross-language communication are identified. The most elite were the Bakshi translators, who specialized in translating and writing letters. The second group is the interpreters. They accompanied foreign embassies, ensured their communication with the host country, and performed diplomatic functions. The third group is the heads of the villages of the service Tatars, who performed, in addition to their direct duties, the functions of interpreters of oral speech. In the XVI century, tolmachestvo played the role of a launching pad for the children of bakshey and podyachy.