The Aga Khan IV, the spiritual leader of the world’s Shi’ite Ismaili Muslims, has died at the age of 88. The wealthy imam, who promoted a moderate form of Islam, has also been known for his multimillion-dollar development projects that have benefited communities throughout Asia and Africa.

Aga Khan, who became the spiritual leader of the world’s millions of Ismaili Muslims at age 20 as a Harvard undergraduate and poured a material empire built on billions of dollars in tithes into building homes, hospitals and schools in developing countries, has died. He was 88.