Saudi Arabia has appointed Prince Mohammed bin Nayef as interior minister, marking a significant move towards a new generation of leaders from the kingdom's ruling family.
Prince Mohammed, a son of the late veteran interior minister Prince Nayef, who died in June, is best known as Saudi Arabia's long-time security chief, and has garnered the praise of Western countries for his role in the campaign against al Qaeda.
He replaces his uncle, Prince Ahmed, who was only appointed as Interior Minister in June.
"Prince Ahmed is relieved of his position as Interior Minister at his own request and Prince Mohammed bin Nayef is appointed," said a royal decree carried on state media on Monday.
The new minister, who had served as assistant minister for security affairs since 1999, effectively led the kingdom's crackdown on Al Qaeda following a wave of deadly attacks between 2003 and 2006.
A main element of his strategy to rout al Qaeda from the kingdom was the introduction of "rehabilitation centres" for former militants.
The move lifts the prince into a critical role for the ruling al-Saud family and one that has until now only been held by the current ruling generation.
Unlike in European monarchies, the Saudi line of succession has so far passed along a line of brothers and is determined within the ruling family who weigh both the seniority and capability of leading candidates.
The interior ministry employs more than half a million Saudis and runs the police, civil defence, domestic intelligence, prisons, the border services and the kingdom's sophisticated security forces.
King Abdullah, the late Prince Nayef, Crown Prince Salman and Prince Ahmed are all sons of Saudi Arabia's founder King Abdulaziz who was known as Ibn Saud.