This volume covers Einstein's correspondence to family, friends and colleagues in the tumultuous post-World War I period, during his rise to international fame after the successful solar eclipse expeditions that confirmed the validity of his general theory of relativity. He began pondering the question of unifying electromagnetism and gravitation and resolving contradictions between relativity and quantum theory. These are also the years during which Einstein divorced, remarried, was being courted by other universities, and awarded numerous honors. Most significantly, he was intensifying his activities on behalf of international reconciliation, protesting the incarceration of left-wing intellectuals, giving free courses to impecunious students, and advocating the establishment of a Hebrew University.