In her recent book Longing for the Lost Caliphate: A Transregional History, Mona Hassan explores the myriad meanings of the caliphate for Muslims around the world through the analytical lens of two key moments of loss in the thirteenth and twentieth centuries. Through extensive primary-source research, Hassan explores the rich constellation of interpretations created by religious scholars, historians, musicians, statesmen, poets, and intellectuals, says a review on the Cornell University website. Hassan fills a scholarly gap regarding Muslim reactions to the destruction of the Abbasid caliphate in Baghdad in 1258 and challenges the notion that the Mongol onslaught signalled an end to the critical engagement of Muslim jurists and intellectuals with the idea of an Islamic caliphate. She also situates Muslim responses to the dramatic abolition of the Ottoman caliphate in 1924 as part of a longer trajectory of transregional cultural memory, revealing commonalities and differences in how modern Muslims have creatively interpreted and reinterpreted their heritage.