Napoleon's Cursed War, by Ronald Fraser

Spain's war against French invaders two centuries ago marked the turning-point of Napoleon's conquest of Europe, the moment when he was stopped and, after six years of slaughter, repulsed. The emperor at the peak of his power found to his bewilderment that he couldn't subdue a quarrelsome backwater. Napoleon's great army was harried across the Pyrenees and fell a year later at Waterloo. "That cursed war with Spain was the main cause of France's misfortunes," he admitted, too late.

Credit usually goes to the Duke of Wellington, whose fewer but better redcoats humiliated the French in Spain and the world. But this fascinating study examines the other decisive element at play, the resistance of ordinary Spaniards to Napoleon's attempt to seize their homeland. Popular uprisings had failed elsewhere, so what made Spaniards invincible?

Madrid confronted the French occupiers on 2 May 1808 in a heroic but doomed insurrection. Men and women in Zaragoza and Girona resisted long sieges. Charismatic leaders commanded armed irregulars who pinned down French troops across Spain, bringing "guerrilla" into the vocabulary of modern war. Ronald Fraser shows that Spain did not rise in a unified crusade. Civilian leaders fought among themselves, mobilised people against the invader, then desperately quashed the revolutionary impulses they had encouraged. Campaigns of sabotage, insurrection and stubborn non-cooperation were driven by a mix of rhetoric, self-interest, clan loyalty, local resentments and fear.

This scholarly work investigates those who waged Spain's popular struggle between 1808 and 1814, and why. It's history from the ground up: momentous events lived by those whose voice is rarely heard. Unlike Fraser's 1979 classic of oral history Blood of Spain, about the Civil War, there's no one left to tell this tale and, in a mostly illiterate society, precious few written accounts. So Fraser builds a mosaic from "shard-like" fragments, a labour of detection that would have swamped anyone with a less sure grip on the sweep of Spanish history.

He moves fluidly from the needlepoint of village records to ideas of nationhood forged by a patchwork of squabbling regions. Execution lists help identify guerrillas' social composition (broadly, artisans and farm labourers); popular mood swings are deduced from weddings deferred, theatre attendances and rumours that French troops carried manacles to press Spanish youngsters into their ranks. And he explains Spain's countrywide guerrilla warfare as the only form of combat the weak could adopt.

French couriers were ambushed for ransom, their mail hijacked, arms and horses stolen, in operations fatally disruptive to Napoleon's war effort. Those responsible straddled the line between guerrilla patriots and highwaymen bandits. Battlefield defeats prompted massive desertions.

Without polemic or romanticism, Fraser gets as close as possible to those through whose eyes he tries to reconstruct events. Goya, in his "Disasters" drawings, depicted with shocking realism the desperation and brutality of this war. Goya lived in Madrid and visited Zaragoza during the atrocities, but Fraser asserts that the artist didn't witness the horrors he portrayed – he was 62 and deaf. Whether or not Goya's pictures of anonymous Spaniards frozen in moments of panic, bloodlust, despair or heroism came from his imagination, eye-witness reports, or from his own razor-sharp observation, here at last are words to accompany them.

Elizabeth Nash's cultural guide to Seville is published by Signal