The Eastern Region Army Group, (GERO), was a military formation of the Spanish Republican Army during the last phase of the Spanish Civil War. It was established in June 1938 as a response to the splitting in two of the territory under the sovereignty of the Spanish Republic after the Central Region Army Group (GERC), under the command of General Miaja, had been set up in the central-southern region of Spain.
This army group of the Spanish Republican military lasted until the Fall of Catalonia on 9 February 1939.
History
The Republican territory split in two
Catalonia had become an isolated enclave following the rebel Aragon Offensive in the spring of 1938. Since the loyalist armies of the former Aragon Front were in a state of disarray after the Republican debacle, the President of the Spanish government Juan Negrín requested the Chief of Staff commander of the Republican Army, Vicente Rojo, to reorganize the Republican forces.
Owing to the loyalist territory having been split in two by the rebels, General Rojo saw the need of establishing two army groups in order to coordinate the specific defence requirements of each zone. Thus after the establishment of the GERO, a new Eastern Army was organized in the Catalan territory, in charge of the defensive line of the Segre River. Meanwhile, in the southern sector the Ebro Army was established, which would have as its goal to eventually reunite the northeastern Republican area with the larger zone further to the southwest. The commander of both armies was a prestigious military figure, General Juan Hernández Saravia, who had been the former commander of the Southern and the Levantine Army.
Right from the moment of its inception the Eastern army group saw action at the Segre Front where there were constant battles along a long defensive line of Republican positions and fortifications. During most of 1938 there would be numerous attacks, counterattacks and skirmishes from both sides along the Segre River. A great number of manpower and material was sent to the Eastern Army in that front, which was a crucial line for halting the devastating advances of the Francoist armies and to keep crucial hydroelectric dams from falling into the hands of the enemy. Eventually the Spanish Republic was able to hold unto that line until the beginning of January 1939 when it became impossible to keep holding the resistance in the Segre against the overwhelming pressure of the rebels.
To complement the battles in western Catalonia the high command quarters of the Republican Armed Forces, led by General Vicente Rojo, were planning a large-scale operation with the aim to reconnect the two isolated enclaves in which the Spanish Republic had been recently divided. Thus on 25 July 1938 Republican troops crossed the Ebro River successfully beginning the Battle of the Ebro. After establishing some bridgeheads, loyalist forces advanced against the rebel-held towns of Gandesa and Vilalba dels Arcs, where after weeks of intense combats the Republican counteroffensive lost steam. Although the Republican operation failed, the Ebro Army dug in within a protracted defensive battle that lasted four months. There were heavy casualties on both sides, but especially on the Republican side, which lost irreplaceable military units and most of its former high morale.
Catalonia Offensive
During the Battle of the Ebro the rebel military had inflicted severe losses to the Republican Armed Forces in Catalonia. At that critical time the GERO still had about 300,000 troops, 360 pieces of artillery and about 200 tanks and armoured vehicles. Also, the General Staff of the Republican Military had kept the commanding structure of the Eastern Region Army Group intact, still under the command of General Juan Hernández Saravia. However, after the numerous casualties —including the many invaluable battle-hardened veterans— , most of the troops of the army group were inexperienced recruits and, owing to the heavy material losses endured, the loyalist troops saw a marked reduction in their ability to operate. To compound matters, the Catalan sector was a bad strategic location bound by Francoist territory on the Spanish side, the Mediterranean Sea on the other, and, even if in the north it still held the French border, non-interventionist France was unreliable at best, when not overtly hostile to the Spanish Republic.
