As is well known, the Ottoman law of succession that was prevalent in the fifteenth and sixteenth centuries considered fratricide a legitimate practice. This was no longer the case in the seventeenth century. This paper traces the transformation of the Ottoman succession from the late sixteenth to the seventeenth century with a view to connect this transformation to dynastic concerns with political legitimacy, and the political empowerment of the Ottoman upper judiciary (the mawali) and the law they represented. As this transformation amounts to a constitutional amendment, such a study of Ottoman succession opens a window to the unwritten Ottoman constitution of the early modern period and thus provides an opportunity to consider early modern Ottoman Empire as a constitutional monarchy of sorts.