
The Carabineros was an armed carabiniers force of Spain under both the monarchy and the Second Republic. The formal mission of this paramilitary gendarmerie was to patrol the coasts and borders of the country, operating against fraud and smuggling. As such the Carabineros performed the dual roles of frontier guards and customs officials.

The 3rd Mixed Brigade, was one of the earliest mixed brigades of the Spanish Republican Army in the Spanish Civil War. It was formed in the fall of 1936 with battalions of the Carabineros corps and saw major action right away in the Defence of Madrid. This brigade also included female combatants —such as Sergeant "La Chata"— and would take part in most of the major battles of the Spanish Civil War, except in the Battle of Jarama.

The 8th Mixed Brigade was a mixed brigade of the Spanish Republican Army in the Spanish Civil War. It was formed at the beginning of the Defence of Madrid in early spring 1937 with battalions of the Carabineros corps and it remained in Madrid all along the war. Its first commander was Carabineros Lt. Colonel Enrique del Castillo Bravo who was succeeded by Carabineros Commanders Emeterio Jarillo Orgaz and José Casted Sena.
The 86th Mixed Brigade, was a mixed brigade of the Spanish Republican Army in the Spanish Civil War. It was formed in March 1937 with battalions of the Carabineros corps. Until its demise it operated mostly in the Sierra Morena area, at the southern limits of the territory held by the Republic.

The 87th Mixed Brigade, was a mixed brigade of the Spanish Republican Army in the Spanish Civil War. It was formed in March 1937 with battalions of the Carabineros corps. Its first commander was Infantry Colonel Carlos Amores Cantos, who was succeeded by Militia Major Andrés Nieto Carmona.

The 222nd Mixed Brigade, was a mixed brigade of the Spanish Republican Army in the Spanish Civil War. It was formed in the summer of 1937 with battalions of the Carabineros corps. Its only commander was the Carabineros Lieutenant Tiburcio Díaz Carrasco.

The 228th Mixed Brigade, was a short-lived mixed brigade of the Spanish Republican Army in the Spanish Civil War. It was formed in the last months of the Civil War with battalions belonging to the Carabineros corps. Its first and only leader was the Carabineros Commander Miguel Bascuñana Sánchez.

José Olaguer Feliú y Ramírez was a Spanish lieutenant general, Minister of War and politician.