The doctrine of Imamat has been central in Shia Islam since the designation by the Prophet Muhammad (s.a.s.) of Hazrat Ali (a.s.) as his successor at Ghadir-Khumm. Among the various interpretations in Shia Islam, the Ismaili Muslims believe in the continuity of the Imamat through a living hereditary Imam descended from Hazrat Ali, through the prophet’s daughter Bibi Fatima (a.s). The current Imam of the Ismailis is His Highness the Aga Khan, who completes his 55th Imamat anniversary as the Ismaili community’s 49th Imam on July 11, 2012. To mark this occasion, we are pleased to provide short selections on the Imamat drawn from numerous writings of historians, theologians, philosophers and poets, Ismailis and non-Ismailis alike.