Columbia subject headings:
Brittany (France)--History.
France--History--Louis IX, 1226-1270.
France--History--Philip II Augustus, 1180-1223.
Pierre, de Maricourt, active 13th century.
Harvard subject headings:
Brittany (France)--History.
France--History--Louis IX, 1226-1270.
France--History--Philip II Augustus, 1180-1223.
Pierre de Dreux, Duke of Brittany, 1190-1250.
Princeton subject headings:
Brittany (France)--History.
France--History--Louis IX, 1226-1270.
France--History--Philip II Augustus, 1180-1223.
Pierre de Dreux, Duke of Brittany, 13th century.