I.E. Tamm is one of the great figures of 20th century physics and the mentor of the late A.D. Sakharov. Together with I.M. Frank, he received the Nobel Prize in 1958 for the explanation of the Cherenkov effect. This book contains a commented selection of his most important contributions to the physical literature, essays on Mandelstam, Einstein, Landau, Bohr and his contributions to Pugwash conferences.