In April 1937, the Nationalists started an offensive against the Republican-held Biscay Province, and by the end of May, the Navarrese troops had reached the eastern side of Bilbao's defenses.

The Republican government then decided to launch two diversionary offensives on the Aragon and Madrid fronts in order to divert Nationalist troops.

The attack against Huesca started on 12 June, led by Lukács who also commanded the 45th Division of the Spanish Republican Army.

Their commander, Ákos Hevesi, and political commissar, Imre Tarr, were both killed as they led from the front.

[6] The failed offensive after the recent May Days in Barcelona, increased the defeatism and the suspicions among the Republican troops in Aragon.