Since Malaysia is a constitutional monarchy, the role of the Yang di-Pertuan Agong is largely ceremonial. The constitution specifies that executive power, theoretically vested in the head of state, are exercised by (or on the advice of) the Cabinet headed by the Prime Minister.
In a feature unique to the Malaysian monarchy, the position is rotated every 5 years between the nine Rulers of the Malay states. The selection of the Yang di-Pertuan Agong initially followed an order based on the seniority (calculated by length of reign) of each Ruler drawn up at Independence in 1957. The original order has at times been varied by the Council of Rulers, which can vote to disqualify a candidate. Minors are automatically disqualified.
After the first cycle of nine Yang di-Pertuan Agong (1957-1994), the order among the state Rulers has followed the order established by that cycle, namely:
The Yang di-Pertuan Agong appoints the (ceremonial) Yang di-Pertua Negeri, or Governors of the other 4 states of Penang, Malacca, Sabah and Sarawak.
The 12th and current Yang di-Pertuan Agong is His Majesty Tuanku Syed Sirajuddin, Raja of Perlis.