AbstractAccording to Western legal historians, the closing of the door of Ijtihād shortly after the formation of the law schools resulted in a long period of sterility in Islamic legal thought and rigid adherence to traditional rules in legal practice. But what did Muslim scholars have in mind when they used the term Ijtihād? Do the sources point to any change in Muslim jurists' understanding of the notion of Ijtihād? And if so, is this change entirely the result of theoretical debate? Drawing on a wide variety of legal sources, supplemented by historiographical and prosopographical sources from the Mamluk and Ottoman periods, I attempt to answer these questions by drawing attention to the relationship between the debate on Ijtihād and the social and political circumstances and legal practices of particular Muslim societies.