This dissertation is a study of the construction of the ‘illegality’ of migration in the Central Mediterranean region from the mid-twentieth century to the present across genres, disciplines and media. Reading a heterogenous set of sources ranging from film to poetry and from parliamentary debates to legal opinions, this dissertation posits the ‘illegality’ of human mobility as a process and not an ontological trait, demonstrating its fluidity and tracking some of its most salient changes over time. Moreover, it argues that these notions of ‘illegality,’ which developed and are interrogated in legal discourse and aesthetic practices, are significantly altered as they circulate across linguistic boundaries even though they continue to be understood as stable and neutral labels. They form a grammar of illegalization the contested semantics of which are simultaneously national and transnational. This dissertation finally suggests that we understand the illegalization of migration as a multilingual object that is written and constructed across multiple discourses and disciplines, and asks that we tend to its grammar as a way to denaturalize and, eventually, attempt to rewrite the ‘illegality’ of human mobility.