Kuchum's sons were captured by Yermak's Cossacks and brought to Muscovy, where they were settled in Yaroslavl and other towns and were authorized to style themselves Tsarevichs of Siberia (Russian: царевичи Сибирские).
For instance, although his son was known as Vasily Abulgairovich, his grandson's name, Roman Vasilyevich, could no longer be distinguished from a native Russian name.
In 1686, the tsar decreed that the dynasties of the king of Imeretia in the Caucasus along with the princes of Siberia and Kasimov were to be entered into the Genealogical Book of the Russian nobility.
At that time, he became interested in the Greek colonies in Crimea and South Russia and produced a remarkable monograph on the medals and coins of the Bosporan Kingdom.
Upon Sibirsky's death, his superb collection of ancient coins devolved upon the Grand Duke Alexander Mikhailovich of Russia.