Basque Auxiliary Navy

Basque Auxiliary Navy Marina de Guerra Auxiliar de Euzkadi Eusko Itsas Gudarostea
Churruca-class destroyer Císcar of the Basque Auxiliary Navy
Active	1936–1937
Country	Spain
Branch	Spanish Republican Navy
Type	Navy
Role	Coastal defence and minesweeping
Engagements	Spanish Civil War
Commanders
Commander	Joaquín de Eguía y Unzueta
Insignia
Naval ensign
Naval jack

The Basque Auxiliary Navy (Spanish: Marina de Guerra Auxiliar de Euzkadi, Basque: Eusko Itsas Gudarostea) was a section of the Spanish Republican Navy operating in the Bay of Biscay between 1936 and 1937. It began operations in October 1936 at the behest of the autonomous Basque Government. The main Basque naval base was at Portugalete.

During the Spanish Civil War, the Second Spanish Republic had allowed an autonomous government in those Basque areas of Spain that had not been taken by the Nationalist faction, like Biscay and parts of Guipuscoa.

The coast of Galicia, along with the Ferrol naval headquarters, became part of rebel-held territory early in the Spanish Civil War. When the Republican Navy became mainly confined to the Mediterranean Sea, after the failure of the blockade of the Gibraltar Strait, its operations in the Bay of Biscay were taken over by the Basque Auxiliary Navy.

Basque Auxiliary Navy ships engaged mainly in minesweeping operations. They also played a key role in the evacuation of civilians who fled as the rebel armies advanced from coastal cities such as Gijón and Santander.

The first naval action against Francoist forces took place on 15 November 1936, when the rebel destroyer Velasco attempted to intercept the armed trawlers Gipuzkoa and Bizcaia (still under their peace-time names of Mistral and Euzkal-Erría). The trawlers were steaming for Biarritz, France, to escort a freighter when they were spotted by the warship 40 miles off Pasaia. In the ensuing battle, the Velasco was hit and limped away, while the Gipuzkoa received some damage on her forecastle, with two seamen wounded.