Born at Rouen (Normandy) to poor parents, Legendre owed the benefit of an education to François de Harlay de Champvallon, the archbishop of his native city, whom he followed to Paris, where he received a canonical at Notre Dame.
Legendre's style has been described as elegant, correct, and his criticism judicious and impartial.
While not a first rank historian, Legendre nonetheless offers information of interest.
Legendre was the first benefactor of the Académie des Sciences, Belles-Lettres et Arts de Rouen.
He also founded the competitive examination prize for the Paris colleges.