Jean David Nau, also known as François l'Olonnais, was reputed to have been one of the most ruthless and barbaric pirates to have ever sailed under the black flag. His career dates from the early part of the golden age of pirates when Tortuga was a safe haven for the pirates and Spanish vessels were the primary target for the buccaneers' depredations. As a child he was sent as an indentured servant, from France, to the French island of Martinique. After serving his term of servitude he moved to the island of Hispaniola, where he joined up with the buccaneers. He seems to have distinguished himself for the French governor of Tortuga, Monsieur de la Place, gave him command of a small ship and sent him out to win his fortune.

His early career while fairly successful seems to be more of note for the fact that it distinguished l'Olonnais for his unusually ferocious treatment of prisoners and earned him a reputation for cruelty that few have surpassed. During the peak of his early successes his ship was wrecked in a storm off the Yucatan coast. While most of the crew survived the wreck, all but l'Olonnais were kill when a group of Spaniards attacked. He managed this feat of cunning by smearing blood and sand over his face and body and hiding among his fallen comrades on the beach. Later, disguised as a Spaniard, he entered Campeche. While the city celebrated his death, he schemed with a band of French slaves to escape the city and return to Tortuga.

L'Olonnais' rein of terror in the Caribbean continued. He partnered with the famous freebooter Michel de Basco and with a fleet of eight ships and 400 men they sacked Maracaibo and Gibraltar in the Gulf of Venezuela. He and his crew made the townspeople's lives into a waking nightmare with rape, murder, and pillage a daily occurrence. Sailing away to Corso Island, a rendezvous of French buccaneers, the pirates shared out the treasure of some 260,000 pieces of eight as well as large amounts of silver plate, silk and jewels.

The reputation for cruelty and depravity of this buccaneer was by now well known throughout the West Indies. One graphic occurrence during the attack on San Pedros places, l'Olonnais questioning the unlucky survivors of a party sent to ambush him. During the questioning, l'Olonnais, becoming frustrated with the prisoners' silence, drew his knife and cut the heart from one of the Spaniards and began to gnaw upon it. Not long after the above incident much his crew defected leaving him with a single craft. Shortly thereafter his ship ran aground on a sand bank and was lost off the Las Petras Islands. Before his plans to outfit a new ship and sail away could be realized he was captured and killed by the native Indians.