Bahrain was a constitutional monarchy in the form of an amirate with an executive-cabinet form of government and a separate judiciary. The amir is head of state and also supreme commander of the Bahrain Defense Force (BDF); he exercises ultimate authority in all matters pertaining to the government. In addition to the amir, Shaykh Isa ibn Salman, principal government officials include his eldest son and heir apparent, Hamad ibn Isa, who is commander in chief of the BDF and deputy prime minister, and several other members of the ruling Al Khalifa. In accordance with the constitution adopted in 1973, the office of amir passes from father to eldest son unless the amir designates another male relative to succeed him. This clause of the constitution is not subject to amendment..