Born into a good Catalan family, he chose to join the French army at a time when the Reaper War was raging.

[3] He was a Catalan gentleman from a prestigious family whose ancestors commanded the defense of Barcelona against Moorish raids on several occasions, notably when Almanzor sacked the city in 985.

[4] His father, Josep de Calvo i Puigesteve, honorary citizen of Barcelona, was a doctor of law, a member of the Council of Aragon and the Royal Audience of Catalonia, and was elected military consul in 1640, along with Aloisio Roca.

[notes 2] His mother descended from a powerful family of Barcelona nobility, which provided the city with a large number of chief councilors.

The third was an ecclesiastic: he was made abbot of Notre-Dame d'Eu by Louis XIV when the siege of Maastricht was lifted in 1676 thanks to the exploits of his brother François;[6] Pierre de Calvo was also honorary councilor to the sovereign council of Roussillon and archdeacon of Elne.

[8] Since the beginning of the Thirty Years' War, Castilian soldiers have been omnipresent in Catalonia, and the local population has had a relatively difficult time of it.

By 1641, the traditional Catalan elite could no longer control the peasants' revolt: unable to stabilize the situation and faced with the advance of Castilian troops, they appealed to France.

He was part of the army that raised the siege of Lérida in 1644 and witnessed the bitter defeat that cost Marshal de la Mothe his post as Viceroy of Catalonia.

In 1648, as a reward for his services and loyalty to the King of France, the barony of Calonge - including, in addition to the town, the lands of Vall-llobrega and Vila-romà - was detached from the county of Palamós for him.

Calvo was judged to be too close to Margarit, and on January 3, 1652, the patent was revoked, officially on the complaints of senior officers who had not yet obtained the rank.

[9] He played an active role in the defense of Barcelona in 1652, but after the victory of the Spanish forces, he watched helplessly as French domination of Catalonia came to an end.

To compensate for the loss of his Catalan properties, on June 18, 165313, he was given the possessions of Antoine de Perapertusa, Viscount of Joch, a Roussillon supporter of Spain who had fled to Barcelona.

He did not lose hope, however, and continued to resist the Spanish troops, managing to dissuade them from laying siege to Roses in the summer of 1653.

With his new regiment, he took part in several military campaigns in Catalonia and Conflent, including the battles of Villefranche-de-Conflent, Puycerda, Cadaqués and Castellon.

Retaining his company as Mestre de camp, he served for a time in Italy and, in 1664, was one of the French troops sent by Louis XIV to help the Holy Roman Empire in Hungary against the Turks.

Seconded by Marshal d'Estrades, Governor of Maastricht, he laid siege to and took the town of Saint-Vith, making a substantial haul and dismantling the place in six hours.

He remained in command of Maastricht until the city was returned to the Dutch and made several forays to keep the enemy at bay, as in May 1678, when he captured the town of Leeuw and took over four hundred prisoners, including thirty-five officers.

On March 25, 1679, when Frederick William I of Brandenburg refused to sign the peace treaty, Calvo was ordered to ravage the duchies of Cleves and Juliers.

Having swum across the Ter, he charged the Spanish lines beyond the Pont-Major and almost took their general, the Duc de Bournonville, prisoner; but the night forced him to be cautious and he preferred to withdraw.

Loyal to the King of France and devoted to Louvois, it was on his orders that he ravaged the country of Liège in 1676, while the French army was besieged in Maastricht.

Paillerolles, a diplomat sent by Pomponne to Maastricht, describes General de Calvo as a cold soldier, cruelly lacking in humanity.

François de Calvo was courageous and intrepid; a true commander, he did not hesitate to pay with his person, “he was of the temperament of the Catinats and Turennes, minus the birth ”.