The Aga Khan Development Network is a network of private, non-denominational development agencies founded by the Aga Khan that work primarily in the poorest parts of Asia and Africa. Aga Khan IV succeeded to the office of the 49th hereditary Imam as spiritual and administrative leader of the Shia faith-rooted Nizari Ismaili Muslim supranational union in 1957. Ismailis consist of an estimated 2530 million adherents.