Columbia subject headings:
Europe--Kings and rulers.
Europe--Politics and government--1492-1648.
Queens--Europe--History.
Regents--Europe--History.
Harvard subject headings:
Europe--History--476-1492--Congresses.
Europe--Kings and rulers--Congresses.
Queens--Europe--History--Congresses.
Princeton subject headings:
Europe--Kings and rulers--History.
Europe--Politics and government--1492-1648.
Queens--Europe--History.
Regents--Europe--History.