The making of the Gibraltar-Spain border: Cholera, contraband, and spatial reordering, 1850-1873

The Anglo-Spanish controversy over Gibraltar has generated a good deal of research in international law and diplomatic history, but little insight into the historical dynamic that forged the British territory's permanent de facto sovereign border with Spain during the third quarter of the nineteenth century. The transformation of a loosely defined neutral zone into a clearly marked line had little to do with statecraft or expansionism, as typically assumed, but rather was a local response to a series of external challenges that increasingly militated for some agreement among local authorities on a precise demarcation. These included broad administrative and fiscal reforms on the part of the British Empire and Spain's liberal governing coalition, the rise of revolutionary Republicanism in Spain, a dramatic uptick in human mobility and migration in the Mediterranean, and the third cholera pandemic.