Hugh Thomas's history (Penguin, 1986), is, I think, regarded as the most complete account of the War available in a single volume. I wonder why it's remembered in almost poetic terms. It was a war fought along ideological, political lines. Ostensibly, at least. People thought that they were fighting for something important, I suppose. And to the extent that it must have contributed towards what Spain is, today, I guess they were right.
Guernica was a small town of the Basque province of Vizcaya, lying in a valley six miles from the sea and twenty from Bilbao. With a population of 7,000, Guernica seemed at first sight to fit undramatically into a hilly countryside of friendly villages and isolated farmhouses. It had been badly damaged by the French in the Peninsular War. It had nevertheless been celebrated, since before records began, as the home of Basque liberties. For the "parliament of Basque senators" used to be held before Guernica's famous oak tree while in the church of Santa Maria the Spanish monarchs, or their representatives, used to swear to observe Basque local rights. (The oak was also a sanctuary for Basque debtors in the old days.) On 26 April 1937, Guernica lay ten miles from the front, and was crowded with refugees and retreating soldiers.
At half-past four in the afternoon, a single peal of church bells announced an air raid.