The Saudi royal court has announced that King Abdullah's half-brother Prince Muqrin bin Abdul-Aziz has been named deputy crown prince, a move that sets out clearly his place as second-in-line to the throne, according to Reuters.

Muqrin bin Abdulaziz once headed the kingdom's intelligence agency and is the youngest son of the founder of modern Saudi Arabia, Reuters reported. The statement says he will retain his title as second deputy prime minister and adviser to the king.

He was named as second deputy prime minister, a position that has in the past been seen as crown-prince-in-waiting in February 2013, according to Reuters.

Muqrin is the youngest of this line, and a dozen or so of his elder brothers still live, but he is one of the few sons of Abdulaziz who has been seen as qualified to one day become king in a system that prizes experience as well as seniority, Reuters reported.

As head of intelligence from 2005 to 2012, Muqrin focused on confronting al-Qaida in the Arabian Peninsula, Reuters reported.

The world's largest oil exporter and U.S. ally is ruled entirely by members of the Al Saud family, according to Reuters.

Thursday's appointment puts to rest questions about who would succeed Crown Prince Salman, the king's designated successor, Reuters reported. Before Thursday's announcement it had been unclear whether Salman would name his half-brother as crown prince or choose his youngest full-brother and former interior minister, Prince Ahmed,

At stake is the future direction of the world's top oil exporter, a country that exerts continuing influence over the world's 1.6 billion Muslims through its guardianship of Islam's holiest sites in Mecca and Medina, according to Reuters.