FONVIELLE, Louis Engine, knight of, French filibuster, born in Thouars in 1655; died in Rio de Janeiro, 18 March 1711. He went to seek fortune with his relative, De Pointis, governor of St. Christophe, in 16'74, was given command of a privateer, and soon acquired such a reputation that Pointis, jealous of his popularity, sent him away. He joined the buccaneers in 1677, was elected a chief, equipped a vessel, and made a successful cruise in the West Indies against the Spaniards. On his return to Santo Domingo in 1678 he found the colony in full revolt against the new governor, and used his great popularity with the buccaneers to restore peace.

Fonvielle was appointed lieutenant of the royal navy in 1779, but in 1781 resumed his privateering expeditions, and became supreme chief of the buccaneers. Through him the French governor, Ducasse, could always obtain the assistance of the filibusters. When De Pointis's expedition against Cartagena was resolved upon in 1697, Ducasse received orders to join it, and Fonvielle sailed with him, with a strong force of buccaneers. After the capitulation of the City, Fonvielle was left by Ducasse to garrison the outer fort and keep the buccaneers away; but, when De Pointis tried to defraud them of their part of the booty, they defied his authority, and plundered the City. When Philip V. became king of Spain, Fonvielle served his cause as faithfully as he had fought the Spanish before, and with a force of small ships assisted Ducasse in 1702 to defeat Admiral Benbow, and carry a convoy with the new viceroy into Cartagena. In 1710 Fonvielle, with 250 filibusters, joined the expedition of Duclerc against Rio Janeiro, and on 19 September entered the City with the French troops; but in the principal square they were surprised by a crossfire from fortified buildings, and retired to the custom house, where they were surrounded by superior forces, and capitulated on the following day. But the terms of the surrender were violated, and Duclerc and Fonvielle were assassinated.