The Requetés (Spanish: [rekeˈtes], from the French requête, “hunting call”) were the Carlist militia of the Traditionalist Communion (CT) during the Spanish Civil War. Wearing red berets, they mostly came from Navarre and were highly religious with many regarding the war as a Crusade. They were often accompanied by priests as field chaplains, who were known for risking their lives to perform the last rites on the battlefield and who also urged the men on. Spanish encyclopedia Sopena of 1965 defines the Requetés:
[A] group of traditionalists whose object is to encourage amongst themselves the goals of the political party, valorous sentiments, physical prowess, initiative, spirit of resistance, and the acceptance of responsibility, and who, during the civil wars of Spain, fought in corps (tercios) in defense of the religious and monarchical traditions.
— Enciclopedia Universal Sopena
Medalla de la Lealdad, 1964.
The earliest use of the term was applied to the Third Battalion of Navarre (Tercer Batallón de Navarra) in 1835 during the First Carlist War, and it was later applied generally to all Carlist combatants.
The Carlist Requetés had been receiving military training during the Second Spanish Republic. During the early and middle periods of the Spanish Civil War the Requeté units were well known as highly motivated and (comparatively) well trained assault troops for the Nationalists. In 1934, a joint Carlist/Monarchist delegation signed a pact with Benito Mussolini to provide financial and material aid to the organisation; as a result, Carlist officers began receiving military training in Italy. Carlist units were instrumental in several Nationalist victories, notably during the tough fighting in and around the two northern provinces of the , Biscay and Gipuzkoa, during the Northern Campaign in 1937. The negotiations with the conspiring generals were tough. General Emilio Mola had appealed to the Carlists for support as he believed the regular Spanish army was inadequate but relations between the two were strained. However, after the assassination of monarchist Calvo Sotelo by Republican Assault Guards in July 1936, the Carlists committed themselves unreservedly to Mola's conspiracy. During the civil war the Carlists were known for engaging in violent excesses, though they generally treated prisoners the most correctly out of the Nationalist forces. The Carlist requetés believed that for every enemy soldier they killed, they would spend one less year in purgatory.
By July 1936, however, Carlism unanimously supported the Nationalist side on the Spanish Civil War. From the start there were serious troubles between the Carlists, especially their then political head Manuel Fal Conde, and the military government. On 8 December 1936, Manuel Fal had to leave temporarily for Portugal after a major clash with Franco.
On 19 April 1937, the Requetés' political branch, the Traditionalist Communion (CT), was "unified" with the Falange and other factions on the Nationalist side into the new FET y de las JONS party by Francisco Franco. Both the Falange and the regent, Prince Xavier of Bourbon-Parma, protested this move, and, after a meeting with Franco, Prince Xavier was expelled from Spain. Due to the necessities of the war, actions against the unification did not go much further, but it meant the loss of all material wealth of the party: buildings, newspapers, etc. Many Carlists refused to join the new party and violence between the factions broke out at the Basilica of Begoña on August 16, 1942, when Falangists attacked a Carlist crowd with hand grenades, causing more than 70 wounded.