Saudi Crown Prince Mohammed bin Salman, power behind the throne
Few people outside Saudi Arabia had heard of Prince Mohammed bin Salman before his father became king in 2015. But since then, the 32-year-old has become the most influential figure in the world's leading oil exporter.
In June 2017 he was elevated to the position of crown prince, replacing his cousin Mohammed bin Nayef - a move that had been widely expected and could shape the direction of the country for decades.
Mohammed bin Salman was born on 31 August 1985, the eldest son of then-Prince Salman bin Abdul Aziz Al Saud's third wife, Fahdah bint Falah bin Sultan.
After gaining a bachelor's degree in law at King Saud University in the capital Riyadh, he worked for several state bodies. In 2009, he was appointed special adviser to his father, who was serving as governor of Riyadh at the time.
Mohammed bin Salman's rise to power began in 2013, when he was named head of the Crown Prince's Court, with the rank of minister. The previous year, his father had been appointed crown prince after the death of Nayef bin Abdul Aziz - the father of Mohammed bin Nayef.
In January 2015, King Abdullah bin Abdul Aziz died and Prince Salman bin Abdul Aziz Al Saud acceded to the throne at the age of 79.
He immediately made two decisions that surprised observers, naming his son minister of defence and Mohammed bin Nayef deputy crown prince. The latter became the first of the grandsons of Ibn Saud, the founder of the kingdom, to move on to the line of succession.
One of Mohammed bin Salman's first acts as defence minister was to launch a military campaign in Yemen in March 2015 along with other Arab states after President Abdrabbuh Mansour Hadi was forced into exile by the Houthi rebel movement.
The campaign has made limited progress over the past two-and-a-half years, seen Saudi Arabia and its allies being accused of human rights violations, and triggered a humanitarian crisis in the Arab world's poorest country.
In April 2015, King Salman made more startling changes to the line of succession, appointing Mohammed bin Nayef as crown prince and his son deputy crown prince, second deputy prime minister and president of the Council of Economic and Development Affairs.
A year later, Prince Mohammed bin Salman unveiled an ambitious and wide-ranging plan to bring economic and social change to the kingdom and end its "addiction" to oil.
The plan, called Vision 2030, envisages increasing non-oil revenue to 600bn riyals ($160bn; £120bn) by 2020 and 1trn riyals by 2030, up from 163.5bn riyals in 2015.
The prince said he wanted to create the world's largest sovereign wealth fund, worth up to $3trn, with money generated by partially privatising the state oil company, Saudi Aramco.
The plan also envisaged changing the education curriculum, increasing women's participation in the workforce, and investing in the entertainment sector to help create jobs for young people.
In April 2017, the kingdom announced plans for a 334 sq km (129 sq mile) entertainment city on the edge of Riyadh offering a range of cultural and sporting activities - including a safari park.
The prince was also seen as having spearheaded a boycott of Qatar, which Saudi Arabia, the United Arab Emirates, Bahrain and Egypt began in early June 2017 over its alleged support for terrorism and meddling in its neighbours' affairs.
Qatar denied the allegations and refused to comply with a list of demands to restore diplomatic and trade links, leading to a stand-off that has yet to be resolved.
In late June, King Salman ended months of speculation by replacing Prince Mohammed bin Nayef as crown prince in favour of his son.
Prince Mohammed bin Nayef was also removed as head of the interior ministry, bringing its security forces under the control of the royal court and his cousin, and reportedly placed under house arrest.
Since then, Prince Mohammed bin Salman has sought to consolidate his power and pressed ahead with his plans for economic and social liberalisation.
An initial step was the reversal of some of the cuts to allowances, bonuses and financial benefits for civil servants and military personnel that were announced in 2016 as declining oil prices and revenues undermined the economy.
In September, a crackdown was launched against perceived opponents of the crown prince's policies. More than 20 influential clerics and intellectuals were detained as the authorities targeted a group allegedly acting on behalf of "foreign parties against the security of the kingdom" - believed to be a reference to Qatar and the Muslim Brotherhood.
Later that month, Prince Mohammed was given much of the credit for King Salman's announcement that a ban on women drivers would end in June 2018, despite opposition from conservatives.
And in October, the prince said the return of "moderate Islam" was key to his plans to modernise the kingdom as he announced the investment of $500bn in a new city and business zone, dubbed Neom.
The next month, Prince Mohammed launched an anti-corruption drive that many analysts said removed the final obstacles to his gaining total control of the kingdom. Eleven princes, four ministers and several influential businessmen were among dozens of people detained.
They reportedly included the billionaire Prince Alwaleed bin Talal and Prince Miteb bin Abdullah, who was also removed from his post as chief of the National Guard - the only security service that was not under Prince Mohammed's control.
In January 2018, Saudi Arabia allowed women to spectate at a football match for the first time, and the following month the kingdom opened applications for women to join its military.