This article is devoted to the problems, connected with translation of terminology in the texts on social and legal relations of Medieval England. Specificity of such texts’ translation exposes the necessity of adequate interpretation of medieval social relations’ peculiar features, represented in special terminology of the sources. Dealing with such specific texts, one has to bear in mind the idea that a historian of nowadays possesses the amount of quite another cognitive meanings and representations in comparison with a human being of the Middle Ages — the fact that complicates an adequate translation of a historical source and modifies its semantic expressiveness. This article also contains a number of principles of translation, based on the author’s experience. They are as follows: one should not always trust historical term itself, but it’s better to look deeper and try fully to take into account the specifics of the activity of a person (including economic one) designated by the term; it’s worth paying attention to set of terms, used in the documents to designate a given person or phenomenon; when translating and interpreting terminology it’s useful to appeal not only to sources, but to historiographical tradition in a given sphere as well; occasionally it’s possible to do without any translation of the term (but to give its interpretation in the footnote) — and mainly in such cases when sense or interpretation of this or that term seem to be rather bulky.