Grand Mufti Sheik Abdul Aziz bin al-Sheik, 63

Preaches from: Saudi Arabia

Sect: Sunni

Influence: A powerful conservative close to the Saudi regime, Abdul Aziz al-Sheik publicly chastised women attending an economic conference in Jeddah in 2004 for being uncovered. He has warned hajj pilgrims not to allow outsiders to divide Muslims, but he has also cautioned that Islam’s greatest affliction is propagated by “its own sons, who [are] lured by the devil [to attack innocents].”

Abu Bakar Bashir, 67

Preaches from: Indonesia

Sect: Sunni

Influence: Bashir emerged in 2002 as a key figure associated with Jemaah Islamiyah, an al Qaeda-affiliated militant group. Although his rhetoric is virulently anti-Western, he calls himself a “simple preacher.” He was released from jail in June after serving two years for conspiracy in connection with the 2002 Bali bombing that killed more than 200 people.

Sheik Mohammed Hussein Fadlallah, 70

Preaches from: Lebanon

Sect: Shia

Influence: Lebanon’s foremost Shia scholar, Fadlallah was considered Hezbollah’s spiritual leader in the 1980s but has long distanced himself from the group. Still, Israel’s recent strikes on the country have outraged him, and he has openly praised Hezbollah’s attacks against Israel. He has also taken the United States and Europe to task for refusing to deal with Hamas and criticized Egyptian President Hosni Mubarak for casting doubt on the loyalty of Shiites. For his part, Fadlallah has angered hard-line clerics in Iran for his efforts to restrain Iran’s influence in the region.

Grand Ayatollah Hossein Ali Montazeri, 84

Preaches from: Iran

Sect: Shia

Influence: A founding father of Iran’s Islamic revolution, Montazeri has become more moderate in recent years and is now the leading critic of Supreme Leader Ayatollah Ali Khamenei. Montazeri has called for closer U.S. relations and more democracy in Iran. The regime kept him under house arrest for more than five years, but Montazeri retains a strong following among reform-minded Iranians.

Sheik Yusuf al-Qaradawi, 79

Preaches from: Qatar

Sect: Sunni

Influence: Qaradawi reaches millions around the world through his popular show on Al Jazeera, Sharia and Life, in which he tackles such controversial topics as Arab reform, jihad, and homosexuality. He is considered a progressive on many social issues, but he became persona non grata in the United States after endorsing the Iraqi insurgency and suicide bombers in Israel.

Moktada al-Sadr, 32

Preaches from: Iraq

Sect: Shia

Influence: The son of revered Shiite cleric Ayatollah Muhammad Sadiq al-Sadr, Moktada emerged early in the U.S. occupation of Iraq as an aggressive and ambitious religious and political figure. Forces loyal to him battled openly with U.S. troops for several months but have now settled into a tense coexistence with both foreign forces and those loyal to al-Sadr’s older and more established rival, Ali al Sistani.

Grand Ayatollah Ali al Sistani, 75

Preaches from: Iraq

Sect: Shia

Influence: As the leading Shia cleric in his country, Sistani is a kingmaker in Iraq’s turbulent political scene. He reportedly favors an Islamic state, but one more moderate than the Iranian variety. Reclusive and in poor health, Sistani has had to fend off a challenge for power from young firebrand Moktada al-Sadr.

Grand Sheikh Muhammad Sayed Tantawi, 77

Preaches from: Egypt

Sect: Sunni

Influence: Tantawi’s position as grand sheikh of Cairo’s Al-Azhar Mosque and head of its renowned university makes him a leading figure in Sunni Islam. Recently, he made waves by endorsing the headscarf ban in France, condemning suicide bombings, and declaring that “extremism is the enemy of Islam.” Critics suggest that he is in the service of the Egyptian regime.