In October 1810 the Allied position in Portugal appeared precarious. Despite defeating Marshal Masséna's French army at Bussaco, Wellington had been forced to retreat to within a few miles of Lisbon. Here the French encountered a massive line of fortifications stretching from the River Tagus to the sea. Built amid great secrecy and on Wellington's specific orders, these Lines of Torres Vedras were the French high-water mark. In February, with his army on the point of starvation, Masséna was forced to retreat and the scene was set for the climactic action of Fuentes de Oñoro. This book examines this crucial campaign culminating in the hard-fought battle that finally drove the French from Portugal.