Outlook Web Desk
The 80-year-old cleric became Supreme Leader in 1989 after the death of the Islamic Republic's founding father, Ayatollah Ruhollah Khomeini.
Born in the north-eastern city of Mashhad in 1939, the son of a religious scholar, Khamenei studied at seminaries in his home city before moving to the Shia holy city of Qom.
As supreme leader, he has either direct or indirect control over the executive, legislative and judicial branches of government, as well as the military and media.
He has quietly emerged as the most powerful person in the Middle East, with uniformed military fighting in Syria and loyal proxies dominant in Lebanon, Yemen and Iraq.
Khamenei's foreign policy has been defined by opposition to the United States and Israel. It’s unlikely he will fully abandon these positions.
Since he became Supreme Leader in 1989, Khamenei has never left Iran. He's never been to any Western country — aside from one visit to New York to attend a 1987 United Nations meeting.
He is the second longest-serving autocrat in the Middle East (after Oman’s Sultan Qaboos) as well as the second longest-serving Iranian leader of the last century, after Shah Mohammed Reza Pahlavi.
Few leaders in the world are as crucial to current global affairs yet as mysterious as Khamenei. He prefers to wield his immense power through Iran's complex web of institutions all effectively under his influence or control.