Salman Bin Abdulaziz Al Saud ascended to the throne of Saudi Arabia after the death of his half-brother King Abdullah, taking the helm of the biggest Arab economy amid political turmoil in the Middle East and tumbling oil prices.

King Abdullah, born in 1924, on Friday was carried by family members into a mosque before his burial, wrapped in a plain shroud, in an unmarked grave in Riyadh. Senior royals gathered to honor the deceased monarch, as did regional leaders. Salman, 79, was named king and Prince Muqrin, 69, another half-brother, was chosen as crown prince.

Salman was named as crown prince in 2012 and takes over as the world’s top oil exporter faces a growing threat of militant attacks at home after joining the U.S.-led military coalition against Islamic State in Syria. Regional rival Iran and its Shiite allies are gaining influence, while plunging oil prices are curbing Saudi Arabia’s capacity to invest.

…“Against the backdrop of the long standing maxim that change in Saudi Arabia occurs at the pace of a snail, the reign of Abdullah has illustrated what that means,” said James Dorsey, a senior fellow in international studies at Nanyang Technological University in Singapore.