The Aga Khan became the spiritual leader of the world’s millions of Ismaili Muslims at age 20. He visited Houston in 2018 and his foundation built the Ismaili Jamath-khana and Center in Sugar Land.; The Aga Khan became the spiritual leader of the world’s millions of Ismaili Muslims at age 20. He visited Houston in 2018 and his foundation built the Ismaili Jamath-khana and Center in Sugar Land.