After the beginning of the Aragon Offensive, the brigade was sent to the Sierra de la Llena sector to try to stop the advance of the nationalists. Shortly after, it would be assigned to the reserve of the 15th Army Corps, but it would not take long for it to be involved again in the fighting in the Battle of the Segre. During the remainder of the campaign, the 59th BM would continue to retreat north, towards the French border, which it would cross on February 9 at the post of Portbou.