After battling a persistent lung infection for several months, King Abdullah of Saudi Arabia has passed away at age 90 . His death was announced overnight Thursday, and mourners have already carried out burial procedures and religious services in his birthplace of Riyadh.

King Abdullah ruled the Saudi Kingdom for 10 years. He was one of four heirs directly in line to succeed King Ibn Saud, founder of Saudi Arabia. King Abdullah’s illustrious father was instrumental in the formation of the current Saudi state. King Ibn Saud, who died in 1953, oversaw the discovery and extraction of rich petroleum reserves deep within his desert land.

During his reign of power, King Abdullah forged lasting relationships with political leaders around the world. He shared a close bond with George W. Bush during his presidency and has been pictured embracing key U.S figures like John Kerry, Jimmy Carter, Donald Rumsfeld, Dick Cheney and more.

A tireless diplomat, King Abdullah worked hard to strengthen his relationships with skeptical western powers after 9/11. He sought to root out religious extremism within the Middle East by making numerous arrests of suspected terrorists. King Abdullah viewed militant groups such as Al Queda as improper distortions of Islam, and frequently advocated against the practice of jihad. He also spent billions of dollars in oil revenue to diversify Saudi Arabia’s economy while encouraging foreign investment.

Though King Abdullah pushed for moderate reform in the Middle East, he was not without his critics. Many of his policies were in step with the practices of Sharia law, adhering to a strict interpretation of Islamic beliefs. Public executions, beheadings, and floggings were all acceptable forms of punishment in his kingdom. Despite international pressure to address social injustices within his country, King Abdullah rarely compromised on his religious framework. He and his long ruling family of royals believed that modern innovations within Islam were against God.

Micah Halpern of The New York Observer studied violent punishment in Saudi Arabia, asserting that “Executioners under King Abdullah had so much work to do that they were often late coming home to their families at night and had difficulty taking vacation and even retiring.”

Some of King Abdullah’s harshest scrutiny came over the treatment of women in his country. In Saudi Arabia, women have faced many restrictions for decades that may seem bizarre from a western perspective. The majority of them are not allowed to drive, venture into public without a male chaperone, or even go swimming in a public pool.

However, King Abdullah has been praised in some circles for his advancement of the female gender. In 2013, he initiated the “King Abdullah Scholarship Program,” which granted thousands of scholarships for young Saudis to study abroad, including women. According to Fortune, women now make up the majority of college graduates in Saudi Arabia. King Abdullah occasionally made small gestures that hinted towards his progressive mindset, such as when he called off the lashing of a woman who was convicted of driving in 2011.

King Abdullah is set to be replaced by his 79 year old brother, Crown Prince Salman. Given speculation over Salman’s questionable health, Saudi Arabia must confront an uncertain transition of power over the coming weeks.