In February 1938 the 45th Division fought briefly at the Extremaduran Front, where it had a measure of success in some combats. But very soon it was rushed again to the Aragon Front where it took part in the effort to halt the overwhelming Aragon Offensive of the rebels. However, the attempt proved futile and the division joined the other Republican units in the massive withdrawal that ensued. By April the rebel troops led by General Antonio Aranda reached the Mediterranean Sea dividing the Spanish Republic in two and the 45th Division would remain locked in Catalonia, becoming detached from the 129th International Brigade, which had remained in the mountainous territory south of the Ebro. Isolated from the remaining Republican territory, the 45th Division was made part of the 5th Army Corps led by Lt. Colonel Enrique Líster. During the months that followed the division managed to rearm and was reinforced by the 139th Mixed Brigade in order to be able to participate in the upcoming Battle of the Ebro. During the offensive the division held its ground against the deadly attacks of the Francoists, ending up with a very high number of casualties, especially the XIV International Brigade —part of the division— which suffered huge losses during the failed attempt to cross the Ebro River near Amposta.