D'Artagnan had a career in
espionage for
Cardinal Mazarin, in the years after the first
Fronde. Owing to d'Artagnan's faithful service during this period, Louis XIV entrusted him with many secret and delicate situations that required complete discretion. He followed Mazarin during his exile in 1651 in the face of the hostility of the aristocracy. In 1652, d'Artagnan was promoted to
lieutenant in the
Gardes Françaises, and fought at the Battle of Stenay in 1654, as well as in sieges at Landrecies and Saint-Ghislaine, then to captain in 1655. In 1658, he became a
second lieutenant in the newly reformed Musketeers. This was a promotion, as the Musketeers were far more prestigious than the Gardes-Françaises. D'Artagnan was famous for his connection with the arrest of
Nicolas Fouquet. Fouquet was Louis XIV's finance commissioner and aspired to take the place of Mazarin as the king's advisor. Fouquet was also a lover of grand architecture and employed the greatest architects and artisans in the building of his
Chateau of
Vaux-le-Vicomte. On 17 August 1661, he celebrated the completion with a most extravagant feast, at which every guest was given a horse. The king, however, felt upstaged by the grandeur of the home and event and, suspecting that such magnificence could only be explained through Fouquet's pilfering the royal treasury, three weeks later had d'Artagnan arrest Fouquet. To prevent his escape by bribery, d'Artagnan was assigned to guard him for four years until Fouquet was sentenced to life imprisonment. In 1667, d'Artagnan was promoted to
captain-lieutenant of the Musketeers, the effective commander as the nominal captain was the king. As befitted his rank and position, he could be identified by his striking burgundy, white, and black livery—the colours of the commanding officer of the Musketeers. Another of d'Artagnan's assignments was the governorship of
Lille, which was won in battle by France in 1667. D'Artagnan was an unpopular governor and longed to return to battle. He found his chance when Louis XIV went to war with the
Dutch Republic in the
Franco-Dutch War. After being recalled to service, d'Artagnan was killed in battle on 25 June 1673 at the
siege of Maastricht, when some believe that a
musket ball tore into his throat.
Location of remains The French historian Odile Bordaz believes that d'Artagnan was buried in in Wolder, a district of Maastricht, the Netherlands. Wolder was Louis XIV's headquarters during the Maastricht siege and he attended mass in the local church every day. In contrast, the archaeologist Wim Dijkman, curator of the historical collections of the city of Maastricht at Centre Céramique, says that there is no historical or archaeological evidence for the claim. On March 25, 2026, during restoration work at the St Peter and Paul Church, subsiding floor tiles around the altar revealed a skeleton buried directly beneath, a site historically reserved for notable figures. Near the remains were a French coin dated around 1660 and fragments of a lead musket ball.
DNA from the teeth was sent to a German laboratory to compare with descendants' genetic material, while other bones were studied in
Deventer to assess age and biological sex. ==Marriage==