Prince Khalifa bin Salman Al Khalifa of Bahrain died at the age of 84 on Wednesday.
The cause of death has not been shared, but according to the state-run news agency of Bahrain, the prince had been receiving treatment at the Mayo Clinic in the U.S.
He is considered one of the longest-serving prime ministers in the world.
Khalifa was born into royalty as the son of former ruler, Sheikh Salman bin Hamad Al Khalifa. He was the uncle of Bahrain’s current ruler, King Hamad bin Isa Al Khalifa.
The Bahraini prime minister maintained power in the region for decades, even during the Arab Spring protests of 2011 that sought to have him removed from power due to allegations of corruption, The Associated Press reports.
Former U.S. Defense Secretary Robert Gates wrote in his memoir he had once advised the king to remove the prime minister from office, saying he was “disliked by nearly everyone but especially the Shia.”
“Khalifa bin Salman represented the old guard in more ways than just age and seniority. He represented an old social understanding rooted in royal privilege and expressed through personal patronage,” said Kristin Smith Diwan, a senior resident scholar at the Arab Gulf States Institute, the AP reports.
His style of leadership rewarded those who supported the Sunni Al Khalifa family, but it was challenged during the Arab Spring by the majority Shiite population of Bahrain.
Crown Prince Salman bin Hamad Al Khalifa was named as the new prime minister on Wednesday, the first since the island nation declared independence in 1971.
As the AP reports, the prime minister was followed by allegations of corruption for much of his career. His name was part of a major corruption practice case against aluminum producer Alcoa that alleged the company was indirectly bribing Bahraini officials.
Former U.S. Ambassador Ronald E. Neumann wrote of Khalifa, “While certainly corrupt, he has built much of modern Bahrain.”