Duke of Orléans was one of the highest ranking titles of the French peerage and dates back to the 14th century. Known as princes of the blood (princes du sang), the title of Duke of Orleans was exclusive to princes of the nearest collateral line of the royal family; thus they constituted a junior branch of the ruling house, second in seniority only to members of the primary line. During the period of the ancien régime the holder of the title often assumed a political role.