Dhruva (Sk). An Aryan Sage, now the Pole Star. A Kshatriya (one of the warrior caste) who became through religious austerities a Rishi, and was, for this reason, raised by Vishnu to this eminence in the skies. Also called Grah-Âdhâr or “the pivot of the planets”.
Source: H.P.Blavatsky - The Theosophical Glossary