The guerrilla war that the Spaniards waged against the French occupiers between 1808 and 1814, combined with the actions of their Portuguese and British allies, contributed significantly to the downfall of Napoleon I. This issue explores, among other things, the historical background of the bloody conflict, the guerrilla leaders and the regions they controlled, guerrilla tactics, their weapons, the French countermeasures, and the importance of priests for the guerrilla movement in Spain.