"Orwell went to Spain in December 1936, ostensibly to write about the civil war, but soon joined the anti-Franco forces. Before going he had gotten in touch with the British Communist Party but its leader was dismissive of Orwell as "politically unreliable" (and subsequently attacked him as "a disillusioned middle class boy"). Orwell then made contact with the Independent Labor Party, once an important British left-wing force whose cranky sectarianism had pushed it to the sidelines. The ILP contact meant that when Orwell decided to fight he enrolled not in the Communist-controlled International Brigades but in the militia of the POUM (Partido Obrero de Unification Marxista), a splinter Marxist group. After over 100 days at the front with POUM militia he returned to Barcelona to meet his wife Eileen who served as a volunteer with the ILP group there.
Orwell was in Barcelona during the internecine fighting that took place there in May as the Communists tightened their grip. He went back to the front, was severely wounded, recuperated, and then had to flee with Eileen to escape arrest and probably execution (the fate of others whom the Communists felt stood in their way). Homage To Catalonia recounts Orwell's personal experience in Spain; it is his view of what happened." (from the 1938 Secker & Warburg edition)
"Bringing all the force of his humanity, passion and clarity to bear, George Orwell examines the bright hopes and cynical betrayal of the Spanish revolution. He describes the discomfort and inefficiency of front-line fighting; the early revolutionary euphoria; the propaganda and distortion perpetrated by both sides; and the tragic collapse of the revolution into warring factions." (from the 1977 Penguin edition)