The wave of arrests and ministerial changes in Saudi Arabia at the weekend has fundamentally transformed the structure of the state as it has existed since the 1960s.  Saudi Arabia has practiced a form of collective leadership since the death of the founder King Abdulazziz in 1953 and especially since the abdication of his son King Saud in 1964.  The crown has descended among the younger sons of Abdulazziz, with each son and his family tending to control one element of the state.  Prince Faisal and then his son controlled the foreign ministry for decades. Prince Sultan controlled the defense ministry; Prince Nayef, the interior ministry and security forces.  Prince Abdullah controlled the National Guard, a well-armed militia recruited from the royal family’s traditional tribal supporters. And Prince Salman served as governor of Riyadh.  The system was intended to avoid the concentration of too much power in any one branch of the family and give all the sons of the founding king a stake in it.

While formal power has always resided with the monarch, in practice the king was expected to consult with other senior members of the royal family and rule by consensus.  The Saudi system of government has been more prime-ministerial than presidential.  In fact, the king has always been concurrently the prime minister, while the crown prince has served as deputy prime minister, and other senior princes have served as ministers in a formal cabinet.  But the system has been fundamentally altered in a number of important ways since the death of King Abdullah and the accession of King Salman in 2015.