The French ‘invasion by stealth’ of her uneasy ally Spain, and the final proclamation of Napoleon’s brother Joseph as king, led in May 1808 to the spontaneous outbreak of a war of resistance which would be waged with unparalleled savagery for the next six years. Spain’s stubborn refusal to submit, despite repeated defeats, was typified by epic sieges such as Zaragoza and Gerona, and by the nationwide guerrilla warfare which tied down huge numbers of the occupiers and gave the modern world a new concept of armed resistance.