[9] General Emilio Mola was in overall command of the Nationalist forces around Madrid and planned an offensive across the Jarama 11 km (6.8 mi) south of the capital.

[11] After a period of heavy rain, the Nationalist offensive began on 5 February with assaults on the Republican positions on the west bank of the Jarama.

[14] Although elements of General Sebastián Pozas' Army of the Centre had begun to take flight, the Republican line was stabilized when Enrique Líster and El Campesino showed up with their veteran brigades on 8 February.

[citation needed] Reinforcements appeared on the east bank of the Jarama and the Republic's army reorganized its defences, forestalling any enemy crossing.

[14] On 11 February a small group of Moroccan regulares crossed the river undetected and crept up to the positions of the Republican XIV International Brigade near the Pindoque railway bridge at Vaciamadrid.

As they had learned to do in the Rif War, the regulares slipped inside the enemy perimeter and silently cut the throats of the sentries.

Nearby, Barrón's column, braving heavy Republican fire, charged across the Arganda Bridge [es] and established a bridgehead on the other side.

Further south, Asensio attacked the village of San Martín de la Vega,[14] where Republican machine gunners brought his advance to grief before being silenced by Moroccan and Legionnaire knifework.

However, the Republicans remained firmly entrenched along the Pingarrón heights on the eastern bank and continued to plaster the Nationalist bridgeheads with artillery fire.

[14] When Junkers of the Condor Legion appeared overhead in support of the Nationalists, Republican planes shot them down and took control of the skies.

However, they were challenged by the arrival of more Italian and Spanish nationalist aircraft and a large scale dogfight was fought over Arganda, and they suffered heavy losses from German 88 mm guns while undertaking ground attack missions.

The rapid withdrawal of the Franco-Belgian battalion meant that Suicide Hill had to be abandoned, but the delay caused by XV International Brigade had slowed the Nationalist advance, masking the weakness of the Republican line.

[22]Another futile and costly attack was made by troops under Juan Modesto from the direction of the Manzanares river to the north on the Nationalist hill-top position at Marronosa.

Other Republican units put down the mutineers and brought them to a cave for a court-martial, but before a sentence could be decided on, Pavlov, the Soviet tank commander, stopped the trial.

[23] Although the Nationalists succeeded in crossing the river and resisted all efforts to dislodge them from their footholds on the other side, the Madrid–Valencia road remained out of reach and firmly in Republican hands.

[citation needed] In March, the Italian Expeditionary Army was likewise thrown back at Guadalajara,[28] ending Franco's hopes of cutting off Madrid.