Following a long delay, the 226th Mixed Brigade was finally established on 22 April 1938 and placed under the 42nd Division of the XV Army Corps, at the time part of the Agrupación Autónoma del Ebro (A.A.E.).

The brigade continued battling the rebel faction between Fayón and Mequinensa, especially at the Fayón-Mequinensa-Fabara road junction, finally being able to occupy the Auts, a semi-arid hilly area east of a bend on the Ebro River.

However, while at the Auts the unit suffered intense aerial bombardment on 29 July and it came under heavy artillery fire between the 4 and 5 August, being prevented from advancing eastwards to capture the towns of Fayón and Mequinensa.

[1][2] After covering some of the many casualties the brigade returned to the bridgehead in order to give a much-needed reinforcement to the 45th Division on 20 September, moving to Hill 496 of the Serra de Cavalls.

On 25 January in the evening the remainder of the 226th Mixed Brigade gathered at the Tibidabo Mountain over Barcelona, but all new recruits disappeared the following morning as the fall of the city was imminent.