King Salman bin Abdulaziz Al Saud acceded to the Saudi throne at the age of 79 in 2015, following the death of his half-brother King Abdullah.
He was governor of Riyadh province for 48 years before becoming defence minister in 2011 and crown prince a year later.
The new king promised continuity after taking power, but his decisions have brought about far-reaching changes in the kingdom.
The most significant has been the promotion of his son, Mohammed bin Salman.
After being named defence minister in 2015, the young prince launched a wide-ranging plan to bring economic and social changes to the country. But he also launched a war in neighbouring Yemen that caused a humanitarian catastrophe.
In 2017, Mohammed was named crown prince by Salman and he set about consolidating his power, detaining rival princes and billionaire businessmen on corruption charges and cracking down on critical intellectuals, clerics and activists.
The murder of the dissident journalist Jamal Khashoggi in 2018 triggered further international alarm and calls for Mohammed's removal, but his father stuck by him.
King Salman was born in 1935, the son of Saudi Arabia's founder, King Abdulaziz (usually referred to as Ibn Saud), and a favourite wife, Princess Hassa al-Sudairi.
The seven sons of Hassa - known as the "Sudairi Seven" - went on to become a powerful faction within the royal family, passing the throne from one to another.
Salman's eldest full brother, Fahd, was king between 1982 and 2005, while two other brothers, Sultan and Nayef, were crown princes.
Salman, the second youngest of the seven, entered government in 1954, when he was named deputy governor of Riyadh.
He was promoted to governor the next year and served five years in the position, which is seen as one of the most important in the country.
After a three-year hiatus, he returned as governor and oversaw Riyadh's transformation from a small desert town into a crowded city of skyscrapers, universities and Western fast-food chains.
He also hosted many visiting VIPs and envoys and helped secure foreign investment.
A leaked US diplomatic cable from 2007 said Salman warned the then US ambassador that for social reasons reforms could not be imposed on the Saudi government, and also that democracy should not be forced on the country, citing the US Civil war as an analogy.
Another cable said Salman was often the referee in disputes within the huge Saudi royal family, with its complex network of competing factions.
Salman also pursued various business interests. Few have been acknowledged, but he reportedly has a stake in the Saudi Research & Marketing Group (SRMG), which owns newspapers and magazines, including the pan-Arab Asharq al-Awsat.
In 2011, following the death of Sultan, Salman was appointed defence minister by King Abdullah, giving him the responsibility for securing the multi-billion dollar arms purchases that Saudi Arabia has used to bolster ties with Western powers.
When Nayef died less than a year later, Salman himself became crown prince.
In 2013, he named Mohammed - his eldest son by his third wife, Princess Fahda bint Falah Al Hathleen - head of the Crown Prince's Court and special adviser with the rank of minister.
As Abdullah's health faded, Salman began to take on many of the duties of king.
When he eventually acceded to the throne, Salman vowed to "continue adhering to the correct policies which Saudi Arabia has followed since its establishment".
As expected, the new king named a younger half-brother, Muqrin, crown prince. But he surprised observers by also naming his son Mohammed minister of defence and Nayef's son, Interior Minister Mohammed bin Nayef, deputy crown prince. The latter became the first grandson of Ibn Saud 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 along with other Arab states after the Houthi rebel movement, which they saw as an Iranian proxy, seized control of the capital Sanaa and forced the president to flee abroad.
The campaign has made limited progress over the past five years. It has also seen Saudi Arabia and its allies being accused of possible war crimes and pushed millions of Yemenis to the brink of famine.
In April 2015, Mohammed bin Nayef was elevated to crown prince and Mohammed bin Salman to deputy crown prince.
A year later, Mohammed bin Salman unveiled a plan, called Vision 2030, to bring economic and social change to the kingdom and end its "addiction" to oil.
In 2017, King Salman ended months of speculation by replacing Mohammed bin Nayef as crown prince in favour of his son. Mohammed bin Nayef was also removed as head of the interior ministry and reportedly placed under house arrest.
Mohammed bin Salman then pressed ahead with both his plans for economic and social liberalisation and his efforts to consolidate his power and silence dissent.
In 2018, for instance, several prominent women's rights activists who had celebrated King Salman's decision to lift the ban on women driving were arrested after they declared that they would campaign to end the repressive male guardianship system.
Mohammed bin Salman denied any role in the murder of Jamal Khashoggi by Saudi agents in Istanbul that year, but there were reports that the king moved to reassert his authority and took a more hands-on role in Saudi policy afterwards.
There was, nevertheless, no attempt to sideline the crown prince and he remained the country's de facto ruler.
The reported arrests of three princes on treason charges in March 2020 - including Mohammed bin Nayef and Salman's only surviving brother, Ahmed - triggered speculation that Mohammed bin Salman was seeking to eliminate rivals to the succession before his aging father died or abdicated.