Battle of Mook

Military operations of the Dutch developed successfully at sea, where marine gaizes twice defeated the fleet of Spaniards. On land, Spaniards continued the siege of Leiden. The basic aim of the campaign of 1574 outlined by prince William of Orange was to relieve Leiden. His brother Louis of Nassau, having recruited mercenaries in Germany was to advance to Maastricht, and in case of flop at Maastricht, to set off for Delft area to join William's troops. On finding out about Orange's plans, the Spanish decided to prevent the troops of Louis from incursion into Brabant, as well as from uniting his troops with those of William, who concentrated 6 thousand infantrymen on Bommel island. To reach this goal, 8 thousand horsemen and appropriate number of infantry were hired in Germany. The command was commissioned to Sancho de Avila's. Late in February of 1574 under a heavy snowstorm, mercenary army headed by Louis crossed the Rein and headed for Maastricht. On the way to Maas river more than a thousand mercenaries deserted. This was aggravated by the impossibility to cross the Maas due to ice drift approaching.

As a result of the battle, the Dutch lost considerable part of their forces and a possibility to carry out any intensive military operations. Though, Avila too could not make use of the great tactical success of the Spanish army due to mutiny. The government backlogged mercenaries a payment for three years. But there was no money.