This paper describes the story of the German translation of Tarski's seminal work The Concept of Truth in Fomalized Languages, originally published in Polish in 1933; the German translation was published in 1935 and became a sensation in logic and philosophy. The story is based on the letters exchanged mostly between Tarski and Kazimierz Twardowski (other persons were involved as well); this collection was discovered 3 years ago. The letters clarify some terminological points, changes in Tarski's views, participation of other people (Kazimierz Ajdukiewicz, Rudolf Carnap, Maria Kokoszyńska and Karl Popper) in doing translation as well as the ways of the early influence of Tarski's work.