When the Francoist offensive against Catalonia began on 23 December 1938, the 1st Mixed Brigade was in the Garrigues area waiting to be reorganized, but it was sent to the Battle of the Segre front in order to plug a breach in the republican lines. For a while it managed to stop the offensive of the Fascist Italian "Corpo Truppe Volontarie" near Les Borges Blanques, but by the beginning of January 1939 it had to retreat towards the north. By 3 February it reached Girona, and on 5 February it still held fast against the Francoist pressure by the banks of the Ter River. Nevertheless, on 9 February in the evening it crossed the French border at Portbou and became disbanded.