In 1937, during the Spanish Civil War, Italians from the Corpo Truppe Volontarie began to serve in mixed Italo-Spanish Flechas (Arrows) units where the Italians provided the officers and technical personnel, while the Spanish served in the rank-and-file.
One, the Flechas Negras Mixed Brigade "Black Arrows" first served in Vizcaya from April 1937.
Flechas Negras Brigade - Col. Sandro Piazzoni Flechas Negras Brigade - Col. Sandro Piazzoni The Flechas Negras Brigade was later expanded to form the Flechas Division.