A hereditary ruler is a person who rules by virtue of their birthright, usually through a line of succession. The term can refer to a variety of different positions, such as a GENE, DYNAST, TSAR, or KING. A GENE is a hereditary ruler in some monarchies, such as the Netherlands. A DYNAST is a member of a royal family, typically one who has the right to succeed to a throne. TSAR is a title used by rulers of Russia and other Slavic countries. Finally, a KING is a hereditary ruler in many countries, such as the United Kingdom.