Columbia subject headings:
Islam--History.
Harvard subject headings:
Caliphate--Early works to 1800.
Constitutional law (Islamic law)--Early works to 1800.
Executive power (Islamic law)--Early works to 1800.
Islam and politics--Early works to 1800.
Islam--History
Kings and rulers--Religious aspects--Islam--Early works to 1800.
Princeton subject headings:
Caliphate--Early works to 1800.
Constitutional law (Islamic law)--Early works to 1800.
Executive power (Islamic law)--Early works to 1800.
Kings and rulers--Religious aspects--Islam--Early works to 1800.
Political science--Religious aspects--Islam--Early works to 1800.