First Carlist War - The Combatants

The Combatants

Both sides raised special troops during the war. The Liberal side formed the volunteer Basque units known as the Chapelgorris, while Tomás de Zumalacárregui created the special units known as aduaneros. Zumalacárregui also formed the unit known as Guías de Navarra from Liberal troops from La Mancha, Valencia, Andalusia and other places who had been taken prisoner at the Battle of Alsasua (1834). After this battle, they had been faced with the choice of joining the Carlist troops or being executed.

The term Requetés was at first applied to just the Tercer Batallón de Navarra (Third Battalion of Navarre) and subsequently to all Carlist combatants.

The war attracted independent adventurers, such as the Briton C. F. Henningsen, who served as Zumalacárregui’s chief bodyguard (and later was his biographer), or Martín Zurbano, a contrabandista or smuggler, who

"soon after the commencement of the war sought and obtained permission to raise a body of men to act in conjunction with the queen’s troops against the Carlists. His standard, once displayed, was resorted to by smugglers, robbers, and outcasts of all descriptions, attracted by the prospect of plunder and adventure. These were increased by deserters..."

About 250 foreign volunteers fought for the Carlists; the majority were French monarchists, but they were joined by men from Portugal, Britain, Belgium, Piedmont, and the German states. Friedrich, Prince of Schwarzenberg fought for the Carlists, and had taken part in the French conquest of Algeria and the Swiss civil war of the Sonderbund. The Carlists' ranks included such men as Prince Felix Lichnowsky, Adolfo Loning, Baron Wilhelm Von Radhen, A. Von Goeben, all of whom later wrote memoirs concerning the war.

The Liberal generals, such as Vicente Genaro de Quesada and Marcelino de Oraá Lecumberri, were often veterans of the Peninsular War, or of the wars resulting from independence movements in South America. For instance, Jerónimo Valdés participated in the battle of Ayacucho (1824).

Both sides executed prisoners of war by firing squad; the most notorious incident occurred at Heredia, when 118 Liberal prisoners were executed by order of Zumalacárregui. The British attempted to intervene, and through Lord Eliot, the Lord Eliot Convention was signed on April 27–28, 1835.

The treatment of prisoners of the First Carlist War became regulated and had positive effects. A soldier of the British Legion wrote that:

The British and Chapelgorris who fell into their hands, were mercilessly put to death, sometimes by means of tortures worthy of the North American Indians; but the Spanish troops of the line were saved by virtue, I believe, of the Eliot treaty, and after being kept for some time in prison, where they were treated with sufficient harshness, were frequently exchanged for an equal number of prisoners made by the Christinos.

However, Henry Bill, another contemporary, wrote that, though "it was mutually agreed upon to treat the prisoners taken on either side according to the ordinary rules of war, a few months only elapsed before similar barbarities were practiced with all their former remorselessness."