This chapter presents an analysis of French border cities and their role in supporting cross-border territorial development processes along the French borders. It provides a picture of their policies, with a focus on ‘cross-border cooperation strategies’ elaborated by four border cities. It begins by describing how actions in the field of monitoring have revealed cross-border metropolitan systems. Then, the analysis sheds light on how French territorial reforms in the 2010s have asserted the role of ‘metropolises’ for territorial cooperation policies. Finally, the chapter turns to the future, describing how the 2021/2027 programming period could be an opportunity to support fully integrated cross-border strategies.