My heroine in An Unpitied Sacrifice was part of the Spanish resistance to Napoleon’s invasion. This resistance was not only in the hands of regular forces. Ordinary Spanish people also fought against the invaders. These guerilleros, as they called themselves (from which we get the name guerrilla), constantly harassed the French army. One Prussian officer fighting for the French said: “Wherever we arrived, they disappeared, whenever we left, they arrived — they were everywhere and nowhere, they had no tangible center which could be attacked.”

For the most part, until the last stages of the war, the French were undefeated on the open battlefield, but their tactics and plans were less successful against irregular troops who could disappear into the population with ease and who knew the country like the back of their hand.

They were given official authorisation and support by the Spanish command, who in 1808 decreed the formation of guerrilla troops, and in 1809 gave them the right to keep any money, supplies and equipment they were able to take from the French.

In one notable case in 1811, a force of between 3000, and 4,500 men ambushed a French convoy, defeating 1,600 troops and taking 150 wagons of supplies and 1,050 Spanish and Portugese prisoners. The convoy was valued at 4 million reales.

In 1812, the reported number of guerilleros was 38, 520, divided into 22 bands. Counter measures proved largely ineffective, as they have against guerrilla warfare ever since.

It might have taken the allied armies to finally push the French out of Spain in 1813, but many historians argue that the Spanish irregular forces made it possible.