This chapter addresses the life and works of Italian transnational anarchist and anti-fascist Camillo Berneri (1897–1937) drawing upon Berneri's archives and original papers. For the first time, this chapter analyses Berneri's work through spatial lenses, investigating the contributions that this can bring to the contemporary fields of critical, radical and subaltern geopolitics. The argument is twofold. First, it argues that the analysis of spaces of exile and transnational solidarity networks are paramount for understanding the trajectories of anarchist anti-fascism between the two world wars. Berneri is an outstanding representative of an entire generation of Italian anarchists and anti-fascists. He was eventually defined ‘the most expelled anarchist of Europe’ due to his innumerable travels and tribulations across the borders of Italy, France, Germany, Belgium, Netherlands, Luxembourg and Spain. Second, it argues that Berneri's writings on the geopolitical problems that the Spanish revolution had to face from 1936, such as the question of the armed defence from Franco's troops and the Italian imperialism in the Balearic Islands, can nourish present-day perspectives in radical internationalism and stateless geopolitics.