The Battle of Segre is the collective name of a series of battles that took place along the Segre River between 4 April 1938 and 3 January 1939 during the Spanish Civil War, after the Nationalist Faction had broken the lines of the Spanish Republican Army in the Aragon Offensive.

[1] Although seldom mentioned in historical works, it was one of the most protracted battles of the Civil War.

After having been overwhelmed in Aragon, the Segre River became for the Spanish Republic a crucial line not only for halting the devastating eastward advance of the rebel armies, but also to ensure that the vital hydroelectric dams of the Pre-Pyrenees did not fall in Francoist hands.

[2] Beginning in April there were constant battles in the Segre Front along a long defensive line of republican positions and fortifications.

[2] Photographer Robert Capa took pictures of the Spanish Republican Navy Marines of the 151 Brigada Mixta who fought in this battle.