The Unión Militar Republicana Antifascista (UMRA, Republican Antifascist Military Union) was a self-described anti-fascist organization for military members in Spain during the Second Spanish Republic. The secret society was created in late 1935, with its membership drawn primarily from the Assault Guard. Its "leading spirit" was Captain Díaz Tendero, who was later to perish at the Mauthausen-Gusen concentration camp. [1]