Ostrowski’s article poses the important question as to why Ivan the Terrible appointed Simeon Bekbulatovich as Grand Prince of all Rus’. Ostrowski describes Bekbulatovich’s identities as khan of the Kasimov Khanate, Chinggisid prince, and a Tatar enrolled in the service of the Grand Prince of Moscow. It is also quite possible that after his baptism, Bekbulatovich became a sincere Orthodox Christian. He was also a warrior and a military commander, a landowner and a slaveholder. But the central event of his life was his mysterious assignment on the Muscovite throne in 1575. It seems, however, that there is no understanding for this mysterious event. Ostrowski's paper doesn't provide an answer to this question. It was likely a Muscovite medieval performance and, unfortunately, today’s modern historians do not understand the meaning and purpose of this episode.