On April 23, 1809 (already in the time of Napoleonic Spain), one of the members of the village council, the Frenchified Vicente Hidalgo Saavedra (with whom he maintained the previously mentioned lawsuit) killed Juan Pedro together with some French soldiers.

Fernández managed to escape by jumping over the walls and fleeing to the field, but his brother was hit by several shots and held in the town hall until May 28, when he was executed by the French and hung on one of the blades of the Old Windmill.

Tío Camuñas became one of the most important guerrillas in La Mancha, with his attacks often taking place on the royal road from Madridejos to Despeñaperros.

Tío Camuñas guerrilla attacked a French detachment in Puerto Lápice on 24 October, stabbing several soldiers and taking the rest prisoner.

In December 1809, with his guerrillas, he escorted Juan Antonio Miranda from Madridejos to Valdepeñas, who traveled with his family from Madrid to Seville as an envoy of the Junta General.

His lieutenant Martín Almarza attacked the French in Santa Cruz de la Zarza (seizing a shipment with three cartloads of salt, killing 13 soldiers and taking four prisoners).

On November 12, 1811, while Tío Camuñas was in the town of Belmonte together with his party, he was surprised and surrounded by some French detachments under the command of General d'Armagnac (head of the column that arrived from Tarancón).

Tío Camuñas was shot on November 13, 1811, dying at the age of 49 and after three years of fighting, being buried in the collegiate church of Belmonte by order of the French general with all solemnity.

In the town where he was shot, Belmonte, he also has a street since 2011 ("Calle Tío Camuñas") and a plaque with some of his most iconic quotes: "Yo no he estudiado nada, pero sé por la luz natural, que un pueblo oprimido es un pueblo que sufre violencia" ("I haven't studied anything, but I know from natural light that an oppressed people is a people that suffers violence").