Jean Siffrein, Cardinal, the son of a poor shoemaker, was born at Vauvèze, in the department of Vaucluse, in 1746. After receiving his education at the seminaries of St Charles and St Garde in Avignon, he left his home at a very early age, and arrived in Paris a poor, friendless adventurer. A funeral oration on the Dauphin introduced him to the public in 1766, and its success led him to take orders, and to devote himself with ardour to the study of pulpit eloquence. Thus obtaining a fair scope, his oratorical powers raised him in quick succession to several appointments. For a eulogy on Fenelon, written in 1770, he was appointed vicar-general of the Bishop of Lombez; a panegyric on St Louis, pronounced before the French Academy in 1772, gained for him the appointment to the abbey of Preneade; and on account of a eulogy on St Augustine, delivered before the assembled clergy in 1773, he was nominated preacher to the court. He now became intimate with men of rank and genius, and, through their influence, was elected a member of the French Academy in 1783. In the following year the valuable priory of Mausoleum, Lihons was bequeathed to him by his friend the Abbé de Boismont. During the troublous days of 1789 Maury's ardent temperament could not brook inactivity. Accordingly, he appeared in the assembly of the states-general as deputy of the clergy of the bailiwick of Péronne. At first he was content to be a silent spectator of the confused wranglings of his associates. In the month of September, however, when the veto of the king came to be discussed, Maury threw aside his taciturnity, and stood forth as a bold defendant of monarchy. Recognised in a short time as one of the champions of the aristocratic party, he often entered the lists against Mirabeau, and his cool courage and ready eloquence made him almost a match for that redoubtable orator. He showed the same self-possessed heroism in the troubled streets of Paris; and never moved abroad without two loaded pistols. On the 9th of November 1789 he threw the Assembly into violent commotion by his bold and persistent opposition to the conversion of church property into national domains. Coming out of the hall on the same day among the infuriated mob, he was received with a universal shout, "To the lamp-iron with Abbé Maury!" "Well," replied the imperturbable abbé, "here he is; when you hang him on the lamp-iron, will you see better there?" and by this ready joke he threw the multitude into convulsions of laughter, and saved his own life. At the dissolution of the Assembly in 1792 he left France. His fame had gone before him; and after meeting the most hearty welcome at Chambery, Brussels, Lièges, and Coblenz, he was summoned to Rome by Pius VI. He was received with great distinction; was nominated archbishop of Nicea in partibus; and was despatched as papal nuncio to the diet assembled at Frankfort for the coronation of Francis II. In 1794 he was appointed cardinal, and bishop of the united see of Montefiascone and Corneto. The terrors, however, which had driven him from his native country followed him to his place of refuge. The armies of republican France entered Rome in 1798, and Cardinal Maury was obliged to skulk for some time in Tuscany, and afterwards to flee to Venice under the guise of a carrier. He then retired to Russia, but returned to Rome in 1799 in the suite of Louis XVIII. After this period, a growing desire to visit Paris, the scene of his early greatness, seems to have gradually extinguished his zeal for the Bourbons. Accordingly, he followed the example of the Holy See by recognising in 1804 the government of Napoleon. In 1806 he returned to the French capital by permission, but found that his political apostacy had excluded him from those brilliant circles in which he was wont to move. Warmly befriended, however, by Bonaparte, Maury was nominated a French cardinal, and appointed chaplain to King Jerome. His elevation to the archbishopric of Paris followed in 1810, and subjected him to the heavy displeasure of Pope Pius VII.; but Maury silently refused to quit his seat at the sovereign pontiff's command, and continued to show for his new master a devotion that verged upon slavishness. At the restoration of 1814 he was ordered to evacuate his archiepiscopal chair. Slowly and unwillingly he bent his steps toward Rome, and on his arrival in that city he was thrown into the castle of St Angelo. His liberation was purchased, after the lapse of a year, by his resignation of the see of Montefiascone and by other humiliations. He lived in retirement till his death in May 1817.

Maury's principal work, Essais sur l'Eloquence de la Chaire, was translated into English by John Neale Lake, 8vo, London, 1783. After its author's death it was reprinted in the original by Louis Siffrein Maury, nephew of the abbe. The same editor published Maury's select works, with a Life, in 5 vols. 8vo, Paris, 1827.