Introduction. Russian translations of Kalmyk official letters housed at Russia’s archives may serve as vivid historical sources both on seventeenth–eighteenth century Kalmyk-Russian relations — and on how translation studies emerged and developed in our country. So, archival files often contain draft translations with original revisions that somewhat show the shaping of the final text and the translation process at large. Materials and methods. The paper examines several Kalmyk-to-Russian synchronic translations of Kalmyk Tayiji Ayuka’s letter dated 21 February 1688. The variants are analyzed with due regard of why the translator would select certain lexemes, replace the already selected ones, and virtually ignore some quite sizeable fragments of the source text. The comparative method proves key to the study. Results. The comparative insight outlines the overall translation strategy: a synchronic translation does focus on the source text and articulate major messages contained therein — but is also replete with additional details. In general, the translation process in not reduced to copying the source text with the aid of target language means, and some distinctions of traced revisions attest to there may have been a transmitter of oral information, though written speech patterns did prevail. The lexical substitutions, corrections of word forms, changes in syntactic constructs clearly illustrate how the translator was making his way through the text.