As soon as the pronunciamento in Madrid was defeated, it became clear that Rebel forces in the regions where the rebellion had succeeded, would march on the capital. To thwart a Rebel advance from Pamplona, forces loyal to the government organized a defence line near Burgos. They made skilful use of a dry river bed that served as a trench. In the centre, the attacking Rebels were stopped in their tracks at the edge of a wood with the help of the loyalist air force. Neither the Carlist Requetes on the Rebel left flank, nor the army units on the right flank managed to take the government positions. When night fell, the Rebels retreated with heavy casualties.