Ahmad ibn Tulun (835-84), the son of a Turkic slave in the Abbasid court of Baghdad, became the founder of the first independent state in Egypt since antiquity, and builder of Egypt's short-lived third capital of the Islamic era, al-Qata'i' and its great congregational mosque. After recounting the story of Ibn Tulun and his successors, architectural historian Tarek Swelim presents a topographic survey of al-Qata'i', a city lost since its complete destruction in 905. He then provides a detailed architectural analysis of the Mosque of Ibn Tulun, which was spared the destruction and is now the oldest surviving mosque in Egypt and Africa, from the time of its completion until today. Rare archival illustrations and early photographs document the changing appearance and uses of the mosque in modern times, while extraordinary 3D computer renderings take us back in time to recreate its architectural development through its early centuries. Plans, drawings, and maps complement the history, while striking modern color photographs showcase the elegant simplicity of the building's architecture and decoration. This definitive and generously illustrated book will appeal to scholars and students of Islamic art history, as well as to anyone interested in or inspired by the beauty of early mosque architecture.