Michel de Grammont was born in 1650, in the southwest of France, to an aristocratic family. Legend has it that, at the age of only fourteen, Grammont became annoyed with a military officer who was in the process of courting his sister. Appalled at the lack of manners displayed by the officer, Grammont challenged him to a duel. He quickly dealt fatal blows to the officer, who, as he lay dying, gave Grammont and his sister much of his estate.
Soon after, Grammont was drafted into the French Navy. He took quickly and easily to life at sea, and even began to lose his upper-class way of speaking and embraced the coarse, often foul dialect of sea captains and pirates. Grammont denounced his privileged family heritage and became a true seaman.
During one of his naval voyages, Grammont and his crew captured a Dutch ship which had been nicknamed "The Purse of Amsterdam" due to the amount of money and precious cargo it carried. Grammont took his share of the loot and spent several days in the French Antilles, where he spent time in brothels and taverns. He gambled much of his money, and eventually earned enough to purchase his own sea vessel. Grammont returned to France and resigned his position with the navy, opting for the life of a pirate at sea.
Grammont went on to stage many successful expeditions, becoming famous for his ruthlessness and small but imposing stature. Between 1678 and 1686, he led four major expeditions in Maracaibo, La Guayra, Vera Cruz, and Campeche.
At about this time, the King of France became increasingly concerned with pirate activity in the Caribbean. To try and stem Grammont's illegal activities, the King offered him a title of Lieutenant of the King for the Province of Santo Domingo. Grammont accepted this position, however, shortly thereafter he assembled a crew of 200 men with 3 ships and headed out for yet another expedition to St. Augustine, Florida.
During this trip, a heavy storm forced Grammont and his crew to change their course, and they headed for the Yucatan. Grammont became separated from the other ships in his fleet, and was never heard from again.