Spanish civil war: Gijón in flames, the burning barracks of Simancas. The Siege of Gijón, one of the first actions in the Spanish Civil War, saw the anarchist militia crushing a small Nationalist garrison in Gijón, between July 19 and August 16, 1936. The militia - nominally fighting in defense of the Republic - laid siege to the Simancas barracks in the city of Gijón. These were defended by about 180 soldiers and Guardia Civil officers who had risen in support of General Franco's rebellion and seized the post for the Nationalists. The battle was remarkable for its viciousness and the stubbornness of the besieged.