"Discovery of Khazaria" - the next, sixth volume of the Collected Works of L.N. Gumilyov. It includes articles by a scientist on the history of Khazaria, as well as the famous book "Discovery of Khazaria," written as a result of a long archaeological expedition in the lower Volga and on the northern coast of the Caspian, during which L.N. Gumilyov managed to geographically identify this ancient disappeared state on the ground. In order for the reader to be able to imagine the problem of Khazarology quite fully, fragments of the main studies on the Khazaria of leading Russian scientists, as well as the chapter of Arthur Koestler's popular work "The Thirteenth Knee," which is first translated into Russian, are prevented in the section "Dialogue of Sources."