The brothers Thomas and Heinrich Mann share a long and intricate history. After a close relationship during their early years as writers, they gradually distanced themselves from each other: differing literary and political views led to a dispute that intensified and eventually erupted into open hostility at the onset of World War I. It was only after the death of their mother in 1923 that the brothers reconciled and reunited in French and American exile. In 1968, the first edition of the correspondence between Heinrich and Thomas Mann was published. The new edition by Katrin Bedenig and Hans Wisskirchen is supplemented by newly discovered documents, including over 80 postcards from Thomas Mann to his brother, as well as a detailed preface that takes into account the current state of research.