A queen consort is the wife of a reigning king (or an empress consort in the case of an emperor). In Brunei, the wife of the Sultan is known as a Raja Isteri with prefix Pengiran Anak, equivalent with queen consort in English, as were the consorts of tsars when Bulgaria was still a monarchy. A queen consort usually shares her husband's social rank and status. She holds the feminine equivalent of the king's monarchical titles, but historically, she does not share the king's political and military powers. A queen regnant is a queen in her own right with all the powers of a monarch, who (usually) has become queen by inheriting the throne upon the death of the previous monarch.