It was organized hastily, the 11th, 12th and 14th divisions were integrated into the Corps, under the command of Enrique Jurado Barrio and mainly Vicente Rojo Lluch.[2][3][n.

1] During the following days, the forces of the IV Army Corps managed to stop the offensive of the Corpo Truppe Volontarie, going on the counterattack.

On March 18, the 11th and 14th divisions converged on Brihuega with the support of 70 Soviet T-26 tanks; the town was almost surrounded by the republicans when a disbandment of its Italian defenders took place, which left behind many prisoners and war material.

[8] The IV Army Corps played a key role in the success of the Casado coup,[9] as it sent several units to Madrid to support the rebel forces in the capital.

A powerful column composed of the 35th, 50th and 90th mixed brigades, and under the command of Liberino González,[10] it managed to recover several key positions for the rebels.[n.