The Tri-Monarchy is a Vinish Political Theory that originates from the Treaty of Fortress Baerne, and Stipulates that three Hereditary Monarchs are the best power sharing arrangement in the Vineyards.

The Tri-Monarchy consists of a Hereditary Lord from the 'Frequesuan Territories,' lands not part of either the Vineyards or Eutopia, the King of Eutopia, and the Lord of Azzan, Thadon, Syl, and Sheoth, King Unifier.