Saudi Arabia on Saturday marks one year since King Salman bin Abdulaziz acceded to the throne of the world's biggest oil exporter, beginning a tumultuous period of change.

Here are facts about Salman, his powerful son Deputy Crown Prince Mohammed bin Salman, and Crown Prince Mohammed bin Nayef:

KING SALMAN

- Born: December 31, 1935. Aged 80.

- Seventh monarch to rule the kingdom founded by his father Abdulaziz Ibn Saud in 1932.

- Holds the post of prime minister and the title of Custodian of the Two Holy Mosques.

- Served around 50 years in charge of Riyadh and its surroundings, overseeing the capital's emergence as a modern city.

- Named defence minister in 2011.

- Named crown prince in 2012.

- Father of a daughter and 10 sons, including Deputy Crown Prince Mohammed bin Salman. Other notable sons are Prince Abdulaziz bin Salman, named assistant petroleum minister in 2004, and Prince Sultan bin Salman who became the first Arab to travel in space when he joined a 1985 mission by the US space shuttle Discovery. Prince Sultan now heads the Saudi Commission for Tourism and Antiquities.

CROWN PRINCE MOHAMMED BIN NAYEF

- Born August 30, 1959. Aged 56.

- Next in line to the throne.

- Holds the posts of interior minister and deputy prime minister.

- Studied political science in the United States and received "advanced law enforcement and counter-terrorism" training in the US and Britain, according to an official biography.

- Has worked in the interior ministry since 1999, initially under his father, overseeing a crackdown on Al-Qaeda, which attacked security officers and foreigners between 2003 and 2007.

- Named interior minister in 2012 upon his father's death.

- Widely respected in the West for his efforts to combat violent extremism.

- Survived with only light injuries an assassination attempt by Al-Qaeda in 2009.

- Married with two daughters, he enjoys swimming, horse riding and hunting, his biography says.

- "I don't think we've seen Mohammed bin Nayef doing a lot in his crown prince capacity" but he has been very much focused on his interior ministry file, a Western diplomat said.

DEPUTY CROWN PRINCE MOHAMMED BIN SALMAN:

- Born August 31, 1985. Aged 30.

- Second in line to the throne.

- Holds the posts of: minister of defence; second deputy prime minister; special adviser to the king; head of the Council of Economic and Development Affairs; chairman of the body overseeing Saudi Aramco, the world's largest crude oil producer.

- Holds a Bachelor of Arts degree in law from King Saud University.

- Served as special adviser to his father when he was Riyadh governor and then crown prince.

- "He's clearly very bright, very intelligent, very on top of all his briefs" and has a large influence on the king, the Western diplomat said.

- Analysts and diplomats have pointed to an emerging power struggle between Mohammed bin Salman and Mohammed bin Nayef.