XYZ Line - Nationalist Offensive

Nationalist Offensive

The Nationalist offensive started on 25 April, with General José Enrique Varela's Army Corps of Castille, Antonio Aranda's Galician corps, and Garcia Valiño's formation, but the advance was halted on 27 April. On 1 May, the Nationalists continued their offensive, advancing on three fronts from Teruel (Varela), the Mediterranean sea coast (Aranda), and a central column moving between them through the mountains (Garcia Valiño). The Nationalists found it slow going due to rainy weather in March and April that slowed the offensive, the difficult terrain that aided the defense of Republican forces being driven back before them, and the dogged determination of the Republican troops, reinforced with new weapons brought in from France: Soviet Supermosca (I-16 Type 10) fighters with four machine-guns, 40 Grumman FF fighters and anti-aircraft guns. On June 13, Castellón fell to Garcia Valiño's corps after several days of fighting but they were halted short of Sagunto where the mountains of the Sierra de Espadán came close to the sea. With the fall of Castellón, the Nationalists had a Mediterranean harbor into which munitions and food could be brought to the Nationalists troops in this front.

The Nationalists were surprised by the resistance of the Republican forces, and General Alfredo Kindelán tried to persuade Franco to abandon the operation. The Condor Legion was exhausted and was eventually withdrawn from the front. Nevertheless, Franco ordered the attack to be continued and Valencia be captured by July 25. By the beginning of July, the Nationalists reinforced the front with three divisions of the Corpo Truppe Volontarie (CTV), led by General Mario Berti, and four divisions of General José Solchaga's Turia Corps. Furthermore, the Nationalists had nine hundred cannon and four hundred aircraft in this front, and had just received about 50 Italian medium bombers (BR.20, SM.79, SM.81). Opposing the Nationalists, the Republicans had the six army corps (Palacio's XVI Corps, Garcia Vallejo's XVII, Vidal's XIX, Duran's XX and Ibarrola's XXII, as well as Güemes's Group A and Romero's Group B) of General Leopoldo Menéndez's Army of the Levante.

On 5 July, Garcia Valiño attacked from Castellón, but he was stopped by the Republican forces led by Colonel Duran and General Menendez at the Sierra de Espadan. The final push of the Nationalist offensive began on 13 July. To the west, Solchaga's corps moved south from Teruel with Varela's corps and the Italian CTV on their flank to the east, and the Garcia Valiño formation tried to advance down the coast. After some determined resistance at Mora de Rubielos and Sarrion, the Republican line in the Sierra de Toro crumbled. The Nationalists then advanced 60 miles along a front of twenty miles wide until they were stopped by the XYZ Line fortifications running east and west from Viver into the Sierra de Espadan.