It was formed in April 1937 in Aragon from the militarized Columna Durruti during the reorganization of the Spanish Republican Armed Forces.

However, when the troops listened to the radio reports of the events by anarchist leader and Justice Minister García Oliver, they refused to intervene and decided to remain in Barbastro.

"General Kléber" commented about the 119th Mixed Brigade of the division that: 'It is totally useless' ("No sirve para nada...")[4] In March 1938 the sweeping Aragon Offensive of the rebel faction caught the 26th Division by surprise and the whole unit retreated eastwards to Catalonia without putting any noteworthy fight.

[4] At the onset of the rebel Catalonia Offensive the division held fast its position at the Tremp bridgehead in an unfruitful effort to stop the sweeping advance of the Francoist armies.

[4] Since the seriousness of the situation did not leave any option but withdrawal, the 26th Division joined the hasty retreat of the defeated republican military units towards the French border.