Biographical study of G. Leets (1896-1975) - the first work published as a separate book on the life path of great-grandfather A.S. Pushkin, associate of Peter I, an outstanding Russian statesman and military leader A.P. Hannibal. Although the book is written mainly from printed sources, it also contains a number of new information, false interpretations of some moments of Hannibal's life and work are refuted. The period of his stay in Estonia (1731-1752) is especially thoroughly considered. The final chapter contains information about the descendants of "arap Peter the Great."