ROCHAMBEAU, Jean Baptiste Donatien de Vimeure, Count de (ro-sham-bo), French soldier, born in Vendome, 1 July, 1725 ; died in his castle at Thore, 10 May, 1807. His father was a lieutenant-general and governor of Vendome. The son was destined for the church, and received his education in the college of the Jesuits at Blois, when the death of his elder brother left him sole heir to the paternal estate. He entered the army in 1742 as cornet in the regiment of Saint Simon, and served across the Rhine, and in Bavaria and Bo-hernia. He was promoted as colonel in March, 1747, was present at the siege of Maestricht in 1748, and after the conclusion of peace won for his regiment a great reputation for precision in drill. On 1 June, 1749, he succeeded his father as governor of Vendome. 

At Minorca, in April, 1756, he led his regiment to the assault of Fort St. Philippe, and greatly contributed to the capture of Port Mahon. He was then created a knight of St. Louis, promoted brigadier-general, and served with great credit in Germany m 1758-'61. He became inspector-general of cavalry in 1769, and lieutenant-general, 1 March, 1780. Count Rochambeau was appointed to the command of the army that was destined to support the American patriots, and obtained from Louis XVI permission to increase it to 6,000 men. He embarked at Brest, 2 May, 1780, and sailed immediately under the escort of Chevalier de Ternay with five ships of the line. Off Bermuda a British fleet attacked them; but it was driven back, and on 12 July they landed safely in Rhode Island. Rochambeau began immediately to erect fortifications by which he prevented Sir Henry Clinton and Admiral Arbuthnot from making an attack that they had concerted. After establishing his headquarters at Newport, he wrote to Lafayette, on 27 August, urging the adoption of a cautious plan of operations, and in an interview with Washington at Hartford, on 22 September, concerted the operations of the following campaign.

He established a severe discipline among his troops, and sent his son to Paris on 28 October to urge the forwarding of money, supplies, and re enforcements. After receiving tidings of the arrival of Count de Grasse with 3,000 men, he had another interview with Washington in which the plan of the Virginian campaign was determined.

He left his quarters, 18 June, 1781, and, marching toward Hudson river, defeated on Manhattan island a detachment of Clinton's army, and crossed the river as if he intended to enter New Jersey, but, instead, joined Washington's army at Phillipsburg, nine miles from Kingsbridge. This skilful movement compelled Clinton to abandon his proposed expedition for the relief of Cornwallis, and obliged the latter to retire from Virginia. After crossing Delaware river at Trenton, the united armies were reviewed by congress at Philadelphia, and Rochambeau and Washington, taking the advance with a small escort, arrived at Williamsburg, Virginia, on 14 September, where they met Lafayette and Count de Saint Simon, who had just landed. They concerted the plan of campaign, and the siege of Yorktown was begun on 29 September Two assaults were led against the place by Saint Simon and Rochambeau, and Count de Grasse having driven back the English fleet, Cornwallis understood that further resist-ante was impossible, and he surrendered. After returning to his winter-quarters, Rochambeau sent Lauzun's legion to the aid of General Greene, and, in April, 1782, marched to invest New York, but the plan was abandoned. After visiting Washington he went to Providence, Rhode Island, and arranged for the embarkation of his army at Boston. He paid again a visit to Washington at New Windsor, and embarked in Chesapeake bay, 14 January, 1783, upon the frigate "Emeraude," arriving in Brest in March following. 

After the surrender at Yorktown, congress presented him with two cannons that had been taken from the enemy, upon which were engraved his escutcheon and a suitable inscription. Louis XVI created him a knight of the Saint Esprit, appointed him governor of Picardy and Artois, and presented him with two water-color paintings by Van Blarenberghe, representing the capture of Yorktown, and the English army defiling before the French and Americans. Before he left Boston, congress had presented him with resolutions that praised his bravery, the services he had rendered to the cause of independence, and the severe discipline he had maintained in his army, and had also instructed the secretary of foreign relations to recommend him to the favor of Louis XVI. He was deputy to the assembly of the notables in 1788, repressed riotous movements in Alsace in 1790, was created field-marshal, 28 December, 1791, and, after refusing to become secretary of war, was appointed to the command of the Army of the North, but resigned, 15 Julie, 1792, and retired to his castle. He was imprisoned in the Conciergerie at Paris in 1793 and narrowly escaped the scaffold. 

In 1804 he was created a grand officer of the Legion of honor by Napoleon and given a pension. One of the four statues forming a part of the Lafayette monument to be erected in Washington by the United States government, will be that of Rochambeau. Lute de Lancival wrote at his dictation his "Memoires du Marechal de Rochambeau" (2 vols., Paris, 1809; translated into English by William E. Wright, London, 1838). His wife died 17 May, 1824

His son, Donatien Marie Joseph de Vimeure Rochambeau, Viscount de, French soldier, born in the castle of Rochambeau, near Vendome, 7 April, 1750; died near Leipsic, Saxony, 18 October, 1813, became in 1767 a lieutenant in the regiment of Bourbonnois, was promoted captain in 1773 and colonel in 1779, and in 1780 accompanied his father to the United States as assistant adjutant-general. On 28 October he was sent to France with cipher dispatches for the king, and in March following he rejoined his father at Newport. He was promoted major-general in 1791, and lieutenant-general, 9 July, 1792, appointed in August following governor-general of the Leeward islands, and pacified Santo Domingo, but in Martinique he was opposed by the royalist army, under the Count de Behagues, the former governor-general, who was also supported by the British. Rochambeau compelled the latter to re-embark; but they returned, 14 February, 1794, with 14,000 men. Although his forces numbered only about 700 men, Rochambeau sustained a siege in the fortress of St. Pierre for forty-nine days, and obtained, on 22 March, an honorable capitulation.

In 1796 he was again appointed governor-general of Santo Domingo; but, being opposed by the commissioners of the Directory, he was removed and transported to France, where he was imprisoned in the fortress of Ham. He was appointed in 1802 deputy commander of the expedition to Santo Domingo, and, landing on 2 February at Fort Dauphin, defeated Tons-saint l'Ouverture (q. v.) at Crete de Pierrot, in the valley of Artibonite, and at Ravine de Couleuvre, and, pursuing his success, destroyed the insurgent army in the passes of the Cohas range. After the death of Victor Leclere (q. v.), 2 December, 1802, he continued the war with vigor; but his severity and the heavy taxes he imposed upon the country displeased the wealthy population, and his army diminished daily by desertions, famine, and yellow fever. Nevertheless, he recaptured Fort Dauphin, defeated Dessalines and Christophe, and twice relieved the garrison of Jacmel, but was besieged at last in Cape Frangais by Dessalines, who was supported by an English fleet. Provisions being exhausted, he evacuated the city, 30 November, 1803, and surrendered to the English admiral. He was transported to Jamaica, and in 1805 was sent to England and imprisoned in a fortress till 1811, when he obtained his release by exchange. He took part in the campaign of 1813 in Germany, and commanded a division of the corps of Lauriston in the battles of Lutzen and Bautzen, and at Leipsic, where he was killed toward the close of the action.