Among the mysteries of Russian history, a special place is occupied by the mystery of the death of the two sons of the Baptist of Rus' Vladimir Svyatoslavich - Boris and Gleb, who were killed on the orders of their elder brother Svyatopolk, who received the nickname Damned in ancient Russian literature. After the expulsion of Svyatopolk, the veneration of princes in the princely family began. The memory of both sufferers remained sacred for Russia. The Russian people, and mainly the princely family, saw in them their intercessors and prayer books. The chronicles contain many stories about miracles of healing that took place at their tomb, about victories won in their name and with their help, about the pilgrimage of princes to their tomb, etc. The surviving historical evidence of the death of two princes gives rise to a range of difficult questions. The historian D. A. Borovkov answers them in his book.