MACKAU, Ange Rene Armand, Baron de (maek-o'), French naval officer, born in Paris, 19 February, 1788; died there, 13 May, 1855. He belonged to an Irish family that had settled in France, was educated at the College of Juilly with Prince Jerome Bonaparte, and on entering the navy was assigned to the same ship with the prince. His promotion was rapid, and was not interrupted by the Restoration. In 1818 the "Golo" was placed under his orders, and he was directed to study the political condition of Colombia and Santo Domingo, which mission he performed successfully. In 1821 he was made commander of the "Clorinde " and sent, to South America to establish political and commercial relations with the Spanish colonies, which had just become independent. During the expedition he sailed for about eighteen months along the coasts of Chili and Peru, and executed some important hydrographic works. In 1823 he was commander of the "Circe," and instructed to open negotiations with Hayti, with a view to its recognition by France, and to demand an indemnity of 150,000, o00 francs in favor of the French colonists, whose property had been confiscated. He succeeded in both objects, and was made rear-admiral after reaching France. In 1832 he was sent to the station of the Antilles and the Gulf of Mexico, and compelled the government of New Granada to give satisfaction for an outrage, and in 1835 for a renewed outrage he bombarded the city of Carthagena and destroyed Fort Boca-Chica. In 1836 he was named governor of Martinique, but during his administration he was more occupied in settling differences between the United States and France than in attending to the wants of that colony. In 1840 he was appointed to the command of a fleet of forty-two vessels, and sent to Buenos Ayres to exact reparation for outrages that had been committed by Rosas on French subjects. In the successful operations that ensued, which were more diplomatic than military, he displayed much ability. On the return of Mackau he was made vice-admiral, a peer of France, and in 1843 minister of the navy and colonies. He published a report on his cruise of 1816-'18 (Paris, 1818) and " Rapport au Roi sur la situation veritable des nouveaux etats de l'Amerique du Sud, et en particulier sur File de Saint Domingo" (1821).