Flechas Negras Mixed Brigade
In 1937, during the Spanish Civil War, Italians from the Corpo Truppe Volontarie began to serve in mixed Italo-Spanish Flechas 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
- 3rd Regimient
- * 1st Battalion
- * 2nd Battalion
- * 3rd Battalion
- * Battery 65/17
- 4th Regimient
- * 1st Battalion
- * 2nd Battalion
- * 3rd Battalion
- * Battery 65/17
- Assault Battalion
- * 1st Company
- * 2nd Company
- Artillery Group
- * IVº Grupo de 75/27
- * Grupo de 100/17
- * Grupo de 105/28
- * Battery 20mm AA
- Engineer Company
- Intendencia Section
- Sanitation Section
Flechas Negras Brigade - Col. Sandro Piazzoni
- 3rd Regiment
- * 1st Battalion "Monte Jata"
- * 2nd Battalion "Bermeo"
- * 3rd Battalion "Munguia"
- * Battery 65/17
- * Engineer Section
- 4th Regiment
- * 1st Battalion "Peña Amarilla"
- * 2nd Battalion
- * 3rd Battalion "Algorta"
- * Battery 65/17
- * Engineer Section
- Assault Battalion
- Artillery Group
- * Group 75/27
- * Battery 149/12
- * Antitank Battery 37mm
- * Battery 20mm AA
- Engineer Company
- Division Truck Unit
The Flechas Negras Brigade was later expanded to form the Flechas Division.