Nasser Khalili is an Iranian-born academic and former art dealer who holds one of the world's largest private collections of Islamic art, with over 20,000 items spanning 1,400 years; the art is both his passion and the basis of his wealth. Nicknamed the secret sultan, Khalili left Iran before the 1979 revolution and now lives in London as a dual U.S.-British citizen. He holds artifacts including rare Koranic manuscripts, paintings, ceramics, glass, and textiles. He started his collection as a teenager, when as his first purchase he bought a 19th century Qajar lacquer pen box. He also owns Japanese Art from the Meiji period, Indian and Swedish textiles, and Spanish metal works. Khalili owns commercial and retail properties in and around London, including tony Mayfair. He is reportedly building an innovative energy-efficient office block dubbed "The Wave." Khalili is co-founder and chairman of the Maimonides Foundation, a charity that promotes interfaith peace and understanding.