Islam's fourth caliph, Ali, can be considered one of the most revered figures in Islamic history. His nearly universal portrayal in Muslim literature as a pious authority obscures centuries of contestation and the eventual rehabilitation of his character. In this book, Nebil Husayn examines the enduring legacy of the nawasib, early Muslims who disliked Ali and his descendants. The nawasib participated in politics and scholarly discussions on religion at least until the ninth century. However, their virtual disappearance in Muslim societies has led many to ignore their existence and the subtle ways in which their views subsequently affected Islamic historiography and theology. By surveying medieval Muslim literature across multiple genres and traditions including the Sunni, Mu'tazili, and Ibadi, Husayn reconstructs the claims and arguments of the nawasib and illuminates the methods that Sunni scholars employed to gradually rehabilitate the image of Ali from a villainous character to a righteous one.