Columbia subject headings:
Castile (Spain)--Foreign relations--To 1500.
Castile (Spain)--History--To 1500.
Castile (Spain)--Politics and government--To 1500.
Monarchy--Spain--History--To 1500.
Harvard subject headings:
Alfonso X, King of Castile and Leon, 1221-1284.
Castile (Spain)--Foreign relations--History.
Castile (Spain)--History.
Castile (Spain)--Kings and rulers--Biography.
Castile (Spain)--Politics and government.
Castile (Spain)--Relations--Germany.
Germany--Relations--Spain--Castile.
Hohenstaufen, House of.
Holy Roman Empire--History.
Holy Roman Empire--Kings and rulers--Biography.
Monarchy--Spain--History--To 1500.
Princeton subject headings:
Castile (Spain)--Foreign relations--History--To 1500.
Castile (Spain)--History--To 1500.
Castile (Spain)--Politics and government--History--To 1500.
Monarchy--Spain--History--To 1500.