This is the first English translation of the seminal book by Katharina Reiß and Hans Vermeer, Grundlegung einer allgemeinen Translationstheorie, first published in 1984. The first part of the book was written by Vermeer and explains the theoretical foundations and basic principles of skopos theory as a general theory of translation and interpreting or ‘translational action’, whereas the second part, penned by Katharina Reiß, seeks to integrate her text-typological approach, first presented in 1971, as a ‘specific theory’ that focuses on those cases in which the skopos requires equivalence of functions between the source and target texts.