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). Kuchum's grandson Alp-Arslan was even installed as a puppet khan of
Kasimov between 1614 and 1627. In 1591, the son of Kuchum, Abul Khayir was the first of his dynasty to convert to
Christianity. His conversion was followed by the conversion of his entire family who eventually assimilated into the Russian nobility. 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. Originally, their legal standing was similar to that of the
mediatized princes of the
Holy Roman Empire. The tsarevichs married into the best Russian families. One of their princesses was the wife of
Peter the Great's maternal uncle, another married a son of the
Georgian king. == Notable representatives ==