Fethullah Gülen, the Turkish cleric accused by Ankara of orchestrating the failed coup attempt in 2016, has died at the age of 83 in his U.S. exile, according to his personal website.

Gülen passed away on Sunday, as reported by the Herkul website, which is banned in Turkey and publishes his sermons. Turkish state television confirmed that the cleric died in a hospital in the United States, where he had lived in Pennsylvania since 1999. He was stripped of his Turkish citizenship in 2017.

Once an ally of Turkish President Recep Tayyip Erdoğan, Gülen became a significant adversary in recent years. Erdoğan has accused him of masterminding the coup, which involved rogue soldiers seizing military aircraft, tanks, and helicopters, resulting in the deaths of approximately 250 people during the violent attempt to seize power.

Gülen, who lived in voluntary exile since 1999, denied any involvement in the coup.

He founded the Hizmet movement, which aims to promote a moderate interpretation of Islam focused on Western-style education, free markets, and interfaith dialogue. The movement gained traction through media support and the establishment of schools across Africa and Asia, while also making significant inroads within Turkish society, particularly in government.

Following the failed coup, the Turkish government blacklisted the Hizmet movement, designating it as a terrorist organization and systematically dismantling its influence in Turkey and abroad.