Marc Rene De, marquis, a French military engineer, born in Angouleme, July 15, 1714, died March 29, 1800. He was descended from an ancient family of Poitou, early entered the army, and took an active part in the campaigns of Italy and Flanders, and in 1741 in the war of the Austrian succession, He devoted himself to military science, in 1747 became a member of the academy of sciences, and established founderies for casting cannon. His innovations in the art of fortification were opposed by the French engineers, but all doubts were dispelled by his successful construction of the fort of Re. He was also employed in the fortifications of Anklam, Stral-sund, and the islands of Aix and Oleron. He became a partisan of the revolution, and relinquished his pension in favor of the national convention. During the reign of terror he obtained a divorce from his first wife, an ac-tress and novelist, and married the daughter of an apothecary. He had given up to the government his founderies, without receiving any equivalent, and was involved in further difficulties by the publication of his works, his various experiments for the improvement of the military art. and the depreciation of paper money.
He bad also executed at his own expense and presented to the government various models relating to fortifications and artillery. His services as a military reformer were publicly acknowledged by the convention and by the council of 500, and some inadequate pecuniary relief was afforded him. He wrote on the campaign of 1757, on the siege of St. Jean d'Acre, ami a historical essay on the founding of cannon, and contributed valuable memoirs to the academy. His great work, La fortification perpendicnlaire, on l'Art defensif superieura l'offensif (11 vols. 4to, Paris, 1776-'96), with illustrations, absorbed a large portion of bis fortune. His system of detached forts inaugurated a new era not only in fortification, but in the attack and defence of fortresses and in strategical science generally. His principles were adopted in the fortifications of Ehren-breit-tcin. Cologne, Sebastopol, Cronstadt, and Cherbourg in the batteries at the entrance of Portsmouth harbor, and in most modern forts for harbor defence. (See Fortification.) II. Charles Forbes Rern de, count, a French statesman, grrandson of the preceding born in London, May 29, 1810, died in Paris. March 13, 1870 He received bis university education in Paris and in his 19th year published a small work on Sweden .In 1830 he became the associate or Lamennais and Lacordaire in founding and editing A Atenir, went with them to Home to plead their own cause in 1831, and on his return opened, with Lacordaire and De Coux, a free Catholic school in Paris, which was closed by the police.
The directors were arraigned before an inferior court for infringing the ordinances on public instruction; but Montalem-bert. having meanwhile become a member of the chamber of peers, transferred his case to that court, and delivered there in his own defence his first public speech. The papal censure which fell upon Lamennais a few years later strengthened Montalembert's attachment to the church, without shaking his liberal convictions, He devoted himself to the study of the middle ages, and published Histoire de Saint Elizabeth de Hongrie (Paris, 1836; English translation by Mary Hackett and Mrs. J. Sadlier, New York, 1854), and an essay Du Yandalisme et du Catholicisme dans Vart (1839). He spoke frequently in the chamber of peers. In 1842 he opposed M. Villemain's bill for the organization of secondary schools, protesting against the " university monopoly" which placed all the schools under the control of the faculty of laymen. In 1843 he published his Manifeste catholique. He was now the recognized leader of the Catholic party.
He delivered three elaborate addresses on the freedom of the church, of education, and of religious orders, in the last of which he eulogized the Jesuits; and in 1847 he founded a religious society to uphold the cause of the Swiss Sonderbund. He spoke in favor of Poland in 1831,1844, and 1846. Early in 1848, in a speech on radicalism, he predicted a revolution in the course of three months. When it broke out he joined the democratic party, published an address avowing republican sentiments, and was elected by the department of Doubs as a deputy in the constituent assembly. Here, however, he acted rather with the conservative party than with the thorough democrats. He opposed the admission of Louis Napoleon, and voted against the new constitution; and toward the close of the session he supported Dufaure's bill for the restriction of the press, and approved the expedition sent to Rome to restore the papal authority. Returned to the legislative assembly by the departments of Doubs and Cotes-du-Nord, he became still more conservative, and was one of the committee which drafted the law of May 31, abolishing universal suffrage. In June, 1851, he had a memorable debate with Victor Hugo on the proposed revision of the constitution.
After the coup d'etat of Dec. 2 he protested against the imprisonment of the deputies, and became more determined in his hostility to Napoleon; but he obtained a place on the second consultative committee, and a seat in the legislative body, where he was almost the only representative of the opposition. Having failed to be reelected in 1857, he lived in retirement, employed in literary labors. An article which he published Oct, 25, 1858, entitled Un debat sur CInde an parhment annlais, led to his prosecution on account of invidious comparisons between the institutions of France and Great Britain. He was sentenced to a fine of 3,000 francs and six months' imprisonment; but both penalties were remitted by the emperor. In 1852 he was elected to the French academy. After his withdrawal from political life, Montalembert busied himself chiefly with the preparation of Les moines d'Occident depuis Saint Benoit jusqu'd Saint Bernard (5 vols Paris, 1860-'67; 3d ed., 1868; English ed., Edinburgh, 1861). He took a lively interest in the progress of the civil war in the United States, his last pamphlet, La xictoire du Nord aux Etats-Unis (Paris, 1865; English translation, Boston, 1866), being a hymn of triumph over the success of the Union arms.
In 1863 he warmly espoused the cause of Poland in the volume entitled Be Vinsurrection polonaise; and in August, at the Catholic congress held in Mechlin, he read a discourse on "A free Church in a free State," which excited angry discussions between the liberal Catholics and ultramontanes. At the approach of the Vatican council he openly declared against defining the doctrine of pontifical infallibility. Besides the works already mentioned, he wrote Bu devoir des Catholiques dans la question de la liberie d'enseignement (1844); Saint An-selme, fragment de Vintroduction d Vhistoire de Saint Bernard (1844); Quelques conseils aux Catholiques (1849); Bes interets catholiques aux XIXe siecle (1852; English translation, 1853); L'Avenir politique de l'Angleterre (1855; English translation, 1856); Une nation en deuil, la Pologne en 1861 (1861); Le pere Laeordaire (1862); and Le Pape et la Pologne (1864). He was one of the editors of the Cor-respondant. An edition of his complete works has been published by Lecoffre (9 vols., Paris, 1861-'8). - See Mrs. Oliphant's "Memoirs of Count de Montalembert" (2 vols., Edinburgh and London, 1872).