Paul Lacroix (April 27, 1806 - October 16, 1884), French author and journalist, was born in Paris, the son of a novelist. He is best known under his pseudonym of P.L. Jacob, bibliophile, or Bibliophile Jacob, suggested by the constant interest he took in public libraries and books generally. Lacroix was an extremely prolific and varied writer. More than twenty historical romances alone came from his pen, and he also wrote a variety of serious historical works, including a history of Napoleon III, and the life and times of the Tsar Nicholas I of Russia. He was the joint author with Ferdinand Séré of a five-volume work, Le moyen âge et la renaissance (1847), a standard work on the manners, customs and dress of those times, the chief merit of which lies in the great number of illustrations it contains. He also wrote many monographs on phases of the history of culture, including Manners, Custom and Dress During the Middle Ages and During the Renaissance Period. Over the signature Pierre Dufour was published an exhaustive Histoire de la prostitution (1851-1852), which has always been attributed to Lacroix. His works on bibliography were also extremely numerous. In 1885 he was appointed librarian of the Arsenal Library, Paris. This article incorporates text from the Encyclopædia Britannica, Eleventh Edition, a publication now in the public domain.