He was born on 1615-16 in Paris and died on April 15, 1695 in Quimperle, France. He was Jansenist who introduced a new method of teaching languages. In 1637 he studied under Abbot Jean Du Vergier de Haurance, one of the fathers of Jansenism, the condemned doctrine advocating that there is no freedom of the will and that redemption is not universal. Lancelot became one of the first hermits of Port Royal, the Jansenist centre near Versailles, Fr. From 1645/46 he taught in the Petites Ecoles, Les Granges, Fr., where the celebrated dramatist Jean Racine was among his pupils. He wrote Nouvelle Methode pour apprendre in langue latine (1644) and Nouvelle Methode pour apprendre la langue grecque (1655), in which the rules of grammar are explained in French rhymes. His famous Jardin des raciness grecques (1657); “Garden of Greek Roots”), an alphabetical vocabulary of Greek words with French translation in rhyming verse form, was used for two centuries. His Nouvelle Methode pour apprendre facilement et en peu de temps la langue italienne, and Methode de plain-chant appeared in 1660.
During the persecution of Jansenism, the Petites Ecoles was dispersed, and Lancelot served as mediator between Port Royal and the pope (1644-69). From 1699 to 1672 he tutored the young princes de Conti and completed his Memoires (published posthumously in 1738)/ je joined the Cistercian abbey of Saint Cyran but for being a Jansenist was exiled (1679/80 to Saint Croix Abbey, Quimperle. L. Cognet’s Claude Lancelot appeared in 1950.
Reference: New Encyclopedia Britannica