Luis de Benavides Carrillo, Marquis of Caracena, a veteran of campaigns in Italy and the Netherlands, was appointed to lead the new invasion of Portugal.

The Spanish crown was also facing financial difficulties, and there was a legitimate fear that the army would have to be disbanded for lack of funds if the war continued.

A further 7,800 men came from Lisbon, under command of António Luís de Meneses, who had defeated the Spanish in the Battle of the Lines of Elvas six years earlier.

A veteran commander who had been defending the Portuguese border with Spain for over 20 years, Meneses was aware that there were any number of ways for Carrillo to invade the country.

As such, he reinforced the border garrisons of Elvas and Campo Maior, hoping to harden the frontier defenses and in doing so influence the route Carrillo would take.

Having been present during the Portuguese victory at Ameixial, Meneses was well aware that the Spanish faced logistical challenges when invading Portugal, and as such he planned to keep Carrillo's army trapped in the border hinterlands as long as possible to wear down their numbers.

He then laid siege to Vila Viçosa, taking the city but failing to capture the citadel, which he was forced to besiege.

[6] The Portuguese decided to exchange land for time, as it was hoped that the rough terrain of the hinterlands would degrade Carrillo's army.

By June, attacks by Portuguese militias were taking a heavy toll on his lines of supply, Vila Vicosa continued to put up an unexpectedly fierce defense, and the Spanish court was demanding action.

The Duke of Schomberg's men gathered around some buildings on the left flank of the Portuguese army, using the structures and a vineyard wall to break up the advancing mass of Spanish cavalry.

The Portuguese cavalry led by D. Luis Melo e Castro, which had until this point played a limited role in the battle, charged and overcame the weakened left flank of the Spanish army.

Almost all of the 1,500 Spanish fugitives who had taken refuge in the many woods around Vila Viçosas for fear of being killed if they surrendered eventually died as a result of their wounds and hunger in the weeks following the battle.

The Battle of Montes Claros effectively ended major combat operations during the Restoration War and definitively secured Portuguese independence from Spain.