Southeast Asia has four monarchies, each with its own unique traits. Brunei is an absolute monarchy, while Thailand, Malaysia, and Cambodia have the constitutional form. The history of these monarchies, including their future prospects, is discussed in the March 2013 issue of the Kyoto Review of Southeast Asia. The essays in the volume give a fascinating overview of how these monarchies survived colonialism and the transition towards democracy. 
In Brunei, Sultan Hassanal Bolkiah has been the absolute ruler since 1984. Professor Naimah Talib argues that the Sultan successfully wields centralized authority by promoting the ideology of Melayu Islam Beraja or Malay Islamic Monarchy. To accommodate the rising middle class, the Sultan welcomed educated elites into his government. To further strengthen his legitimacy, he used the country’s oil revenues (accounting for 70 percent of its GDP) to implement generous welfare programs which allow Bruneians to enjoy one of Asia’s highest standards of living. What’s more, there is no personal income tax in Brunei.