Rudolf Strothmann (1877-1960) played a pioneering role in the scholarly exploration of Shīʿī Islam in Western, especially German, scholarship. Between 1910 and 1923, he published many pathbreaking studies on the Zaydiyya, a sub-sect of Shia Islam that emerged in the eighth century, consulting primarily the recently purchased collections of Yemeni Zaydī manuscripts in Berlin. At the same time Strothmann delved into the literature...