Orwell arrived in Barcelona in December 1936, less than six months after the military uprising which started the Spanish Civil War. Catalonia was the most left-wing region of Spain, and Orwell found a city under revolutionary control. Tipping was banned, and even the barbers' shops displayed political slogans. The wealthy were keeping their heads down and biding their time. One gets some sense of the horrible extreme polarisation of Spanish society - the Marxist/fascist divide which had developed by the 1930s and which underlay the civil war.
Orwell enlisted in a workers' militia in which the men were allowed to argue with the officers (he insists that the system worked). Most of the men, of course, were Spaniards - proud, often very young, often illiterate, and in some cases even unsure of their political affiliation. There were other volunteers too, including other Brits, Americans and anti-Nazi Germans. Orwell, who had been in the officer cadet corps at Eton, had more idea how to handle a rifle than most of his comrades. He was made a corporal, and eventually an acting lieutenant. He well describes the cold, the abysmally poor equipment, the troops shouting opposing political slogans at each other's trenches, and the boredom as heroic battles largely failed to materialise.
Orwell went on leave to Barcelona in April 1937. By this time, the revolutionary ardour had cooled and the city had become altogether more capitalist - but serious trouble was brewing. A curious feature of the Spanish Civil War is that the feuds within the Republican camp were frequently as bitter as the overarching fight against the Francoists. There were fault-lines between democratic liberals and far-left revolutionaries, between Marxists and anarchists, and between Stalinists and Trotskyists. The local Communist Party (the PSUC) resisted pressure for a full-scale socialist revolution - which would have messed up Russian foreign policy - and accused the anti-Stalinist POUM of being Trotskyists and fascist sympathisers. It was the POUM militia that Orwell joined, without initially having much idea what it stood for politically.
The tensions between the disparate parts of the anti-Franco coalition erupted into rioting and fighting on the streets of Barcelona in May 1937. Orwell found himself in the midst of the violence, which he found a more distressing experience than fighting on the front line, though he took little active part in it himself. The unrest ended with victory for the governmental and Communist forces and the defeat of the anarchists and the POUM, who were blamed for instigating the trouble. A Soviet-style crackdown on the defeated organisations followed.
Orwell returned to the front line, only to be shot in the throat shortly afterwards by a sniper. Miraculously, he survived and was invalided out of the fighting - only to find himself dodging the authorities in a Barcelona in which his POUM comrades were being rounded up and thrown into jail. His wife's hotel room was pulled apart by policemen whom he suspected were Communist Party members. He fought against his ingrained English instinct that, if you hadn't done anything wrong, you didn't need to be scared of the police - a dangerous notion to have in 1930s Spain. A strange sort of fugitive, he slept rough by night and posed as a bourgeois English tourist by day. Finally, he managed to get on a train and slip past the border guards into France.
One of the most striking things about Orwell's memoir is that he seems to have had little idea that the Francoists were going to win the war. There is a rather desperate Life of Brian feel about his descriptions of the endemic conflicts between different sorts of anti-fascists. As far as he was concerned, there was still everything to play for, and a Republican victory was a realistic prospect - even if it would, as he realised, merely mean one kind of dictatorship rather than another.
Orwell ends up back in the safety of his native southern England - still familiar and sleepy, and about to sleepwalk into World War II. The last paragraph in the book is classic Orwell:
Down here it was still the England I had known in my childhood: the railway-cuttings smothered in wild flowers, the deep meadows where the great shining horses browse and meditate, the slow-moving streams bordered by willows, the green bosoms of the elms, the larkspurs in the cottage gardens; and then the huge peaceful wilderness of outer London, the barges on the miry river, the familiar streets, the posters telling of cricket matches and Royal weddings, the men in bowler hats, the pigeons in Trafalgar Square, the red buses, the blue policemen - all sleeping the deep, deep sleep of England, from which I sometimes fear that we shall never wake till we are jerked out of it by the roar of bombs.