This chapter explores and develops the relationship between two key concepts that have been central to Gary Jacobsohn’s work over the past decade or so: constitutional identity and constitutional revolution. In particular, it addresses the issues of (1) how and to what extent constitutional revolutions impact constitutional identity, (2) whether they do so in a single or uniform way, and (3) the implications of the broadening of the concept of constitutional revolution in the recent book for the possibility of the “substitution of one constitutional identity for another.” With respect to the latter, the chapter identifies a certain resistance in the new book to the idea of a new constitutional identity but argues both that its thesis is perfectly consistent with this possibility and that the idea provides the best way to understand certain constitutional revolutions.