He was originally destined for the church and was brought up at the Jesuit college at Blois, but after the death of his elder brother he entered a cavalry regiment, served in Bohemia and Bavaria and on the Rhine, and in 1747 had attained the rank of colonel He took part in the siege of Maestricht 111 1748, became governor of Vendôme in 1749, and after distinguishing himself in 1756 in the Minorca expedition was promoted brigadier of infantry. In 1758 he fought in Germany, notably at Crefeld, received several wounds in the battle of Clostercamp (1760), was appointed maréchal de camp in 1761 and inspector of cavalry and was frequently consulted by the ministers on technical points. In 1780 he was sent, with the rank of lieutenant-general, in command of 6000 French troops to help the American colonists under Washington against the English. He landed at Newport, Rhode Island, on July 10, but was held here inactive for a year, owing to his reluctance to abandon the French fleet, which was blockaded by the British in Narragansett Bay. At last, in July 1781, Rochambeau's force was able to leave Rhode Island and, marching across Connecticut, joined Washington on the Hudson. Then followed the celebrated march of the combined forces to Yorktown, where on September 22 they formed a junction with the troops of Lafayette; as the result Cornwallis was forced to surrender on October 19.
Throughout, Rochambeau had displayed an admirable spirit, placing himself entirely under Washington's command and handling his troops as part of the American army. In recognition of his services, Congress voted him and his troops ‘the thanks of the nation and presented him with two cannon taken from the English. These guns, which Rochambeau took back to Vendôme, were requisitioned in 1792. On his return to France he was loaded with favours by Louis XVI and was made governor of Picardy. During the Revolution he commanded the Army of the North in 1790, but resigned in 1792. He was arrested during the Terror, and narrowly escaped the guillotine. He was subsequently pensioned by Bonaparte, and died at Thoré (Loiret-Cher).
A statue of Rochambeau by Ferdinand Hamar, the gift of France to the United States, was unveiled in Lafayette Square, Washington, by President Roosevelt on May 24 1902. The ceremony was made the occasion of a great demonstration of friendship between the two nations. France was represented by her ambassador, M. Cambon, Admiral Fournier and General Brugère, a detachment of sailors and marines from the warship "Gaulois" being present. Representatives of the Lafayette and Rochambeau families also attended. Of the many speeches perhaps the most striking was that of Senator Henry C. Lodge, who, curiously enough in the circumstances, prefaced his eloquent appreciation of the services rendered to the American cause by France by a brilliant sketch of the way in which the French had been driven out of North America by England and her colonists combined. General Brugère, in his speech, quoted Rochambeau's words, uttered in 1781: "Entre vous, entre nous, a La vie, a La mort." A "Rochambeau fête" was held simultaneously in Paris.
The Mémoires militaires, historiques et politiques, de Rochambeau were published by Luce de Lancival in 1809. Of the first volume a part, translated into English by MWE Wright, was published in 1838 under the title of Memoirs of the Marshal Count de R. relative to the War of Independence in the United States. Rochambeau's correspondence during the American campaign is published in H Doniol, Hist. de la participation de la France en l'établissement des Etats Unis d'Amérique, vol. v. (Paris, 1892). See Duchesne, "Autour de Rochambeau" in the Revue des faculté's catholiques de l'ouest (1898-1900); E Gachot, “Rochambeau” in the Nouvelle Revue (1902); H de Ganniers, "La Dernière Campagne du maréchal de Rochambeau" in the Revue des questions historiques (1901).