Alexander Fedorovich Hilferding (1831-1872), diplomat, major statesman and public figure, prominent Slavic scholar, historian and philologist, folklorist, left a rich scientific heritage in history, linguistics, folklore of the Western and southern Slavs. But a special place in his work was occupied by the history of the disappeared South Baltic Slavs, with whom the domestic, Western European and Arab traditions associate the annalistic Varangians and Russia. This publication includes the fundamental studies of the scientist, which laid the foundation in science for the study of the South Baltic Slavic civilization, which aroused admiration among its modern Germans and played a huge role in the history of Northern and Eastern Europe.