FREDERICK WILLIAM, Duke of Brunswick, the fourth and youngest son of Charles William Ferdinand, was boru October 9,1771, and educated for the military profession. In 1786 the king of Prussia named him successor of Ins uncle Frederick Augustus, duke of Oels and Berustadt, who died in 1805. Ho wont to Lausanne, spent two years iu Switzerland, end ou his return was made captain in a Prussian regiment of infantry. In 1792 ha was with the Prussian army in France, and was twice wounded. After the peace of Basel ho obtained a regiment, and in 1801 married the princess Mary of Baden, by whom he had two eons, Charles and William. After 1306 he took part iu the war against, France, with all the ardour which the oppression of Ger many and his father's unhappy fate inspired. Ile was taken prisouor with BRieber at Lubeck. His eldest brother the hereditary duke dying without children in September 1806, and his two other unmarried brothers having been declared incapable of reigning on account of incurable blindness, he would have succeeded to the government of Brunswick on the death of his father; but tho peace of Tilsit and the will of Napoleon decided otherwise. From that time ho lived at Brucheal, where ho lost his consort in April 1808. At the beginuing of the war between France and Austria, in 1809, ho raised a free corps in Bohemia. After the total defeat of the Austrians, the duke resolved to leave Germany, and with a corps of 700 cavalry and 800 infantry, commenced in July that memorable and masterly retreat which gained him such deserved reputation. After some skirmishes he reached Brunswick on the 31st of July, but did not enter the city. Thera was no time for rest; three bodies of troops, each much more numerous than his own, were advancing against him. On the 1st of August the Weetphalinn general Roubel met the duke at the village of Odper, near Brunswick, and a battle ensued, in which Reuben! 4000 men not only yielded to the 1500 Brunewickers, but left the only way open by which they oould escape.
By a series of skilful manceuvres the duke deceived his pursuer*, crossed the Weser, broke down the bridge behind him, and having completely baffled his enemies, reached Eldieth on the 6th of August, where be took possession of a sufficient number of vessels in which ho embarked his troops during the night, and on the 7th iu the morning, hoisting English colours, sailed for Heligoland, where he arrived on the 8th, and ou the 10th proceeded with his corps to England. lie was received in England with the greatest joy ; his troops were taken into the English service and employed iu the Peninsula, where they distinguished themselves. The duke had a pension of 60001. a-year granted by the parliament till he returned to his own dominions iu December 1813, where he was received with extraordinary entliudasni, and with expectations which ho was unhappily unable to fulfiL lie was one of the most liberal and minded princes of his age. He was sincerely desirous of promoting the welfare of his subjects; but, wanting to accomplish it at once, he overlooked the ordinary forms : findiog nothing to support him in the constitution of the country, which had been completely changed, and being surrounded by interested or prejudiced counsellors, nume rous mistakes were committed. His military establishment was too great for the dilapidated state of the finances, and indifference, if not aversion, took the place of the affection of his people. The rest is known. With his famous Black Hussars _he joined the Duke of Wellington in 1815, and fell gloriously at Quatre-Bras on the 16th of June 1815.