This is both the first complete annotated edition of the letters exchanged by these major twentieth-century Scottish poets and the first major exploration of their long friendship and literary association. Spanning nearly fifty years, from 27 July 1934 to 23 July 1978, this engaging correspondence offers a revealing and sometimes intimate look at their lively dialogical exchanges on a broad range of topics from major historical events such as the Spanish Civil War and WW II, to the mundane challenges of daily life. The introductory chapters chart the development of MacDiarmid and MacLean's enduring friendship in relation to their quite different literary contexts and careers, discuss MacLean's significant contributions to MacDiarmid's Golden Treasury of Scottish Poetry, and situate MacLean's literary innovations in terms of Gaelic modernism. They thus provide comparative critical insights into the influence of cultural nationalism on each writer's developing poetics, their work as translators, and their mutual influence on each other's careers. These private letters in which culture, politics, and modern history intersect offer a fascinating glimpse at the creative processes and collaborative work of Hugh MacDiarmid and Sorley MacLean. Key Features: * The first complete annotated edition of the correspondence between the two poets * The only major exploration of MacDiarmid and MacLean's friendship and literary association * Full biographical and historical Introduction, bibliography and appendices