THADDEUS, a Polish general, celebrated for his lofty patriotism, was descended of a noble but not opulent family, in the province of Lithuania, and born in 1756. He was educated at Warsaw, and was afterwards sent, at the expense of the state, to finish his studies at Paris. After an absence of several years he returned home, and became a captain in the Polish army. An unfortunate attachment made it necessary for him to go abroad for a time, and he proceeded to North America, served as adjutant to General Washington in the War of Independence, was decorated with the order of Cincinnatus, and returned to his own country, where he lived in retirement until 1789. About this period he was promoted to the rank of general-major by the Diet, which was then making vain efforts to restrain the influence of foreign powers. Kosciusko was at that time little known; but in 1792 the affair of Dubienka, where with 4000 men he defended for six hours a post attacked by 15,000 Russians, gained him much reputation. He served with equal distinction, during the whole campaign of that year, under the young Poniatowski; but the weakness of Stanislaus rendered fruitless the most generous efforts to maintain the independence of his country. He submitted to the conditions which were imposed upon him by Russia, and under the appearance of a treaty of peace, signed the ruin of Poland. Many of the best officers of the Polish army, Kosciusko in the number, resigned in indignation, and retired to various parts of Germany. When the revolution broke out in Poland in 1794 he was appointed generalissimo of the insurgent patriots, and invested with dictatorial power. Hastily organizing a corps of 5000 men, he marched at their head against the Russians, who were advancing upon Cracow with greatly superior numbers. Destitute of cavalry and artillery, he met the enemy at Wraclawice, and, after a combat of four hours, completely defeated them. This first success produced a general rising; Warsaw was delivered from the presence of the Russians; and Kosciusko soon saw himself at the head of an army of 50,000 men, including about 25,000 regular troops. With this comparatively small force the Polish general-in-chief had to make head at once against the Russians and the Prussians. Frederick William II., who had just failed in his contest with the French, appeared desirous to avenge himself for this affront on the Poles; and, at the beginning of 1794, he marched against Warsaw, at the head of 40,000 men. Kosciusko, who, upon this point, could not oppose to him more than 15,000 men, had nevertheless the courage to attack him at Szczekocin, on the 8th of June 1794; but after a murderous combat, in which he had two horses killed under him, he was obliged to retire to the entrenched camp that covered the capital, where, for two months, he resisted the reiterated assaults of the enemy. At the same time he contrived to keep in order a furious populace, prone to give way to the greatest excesses. Scarcely had he been delivered from the Prussians, in consequence of the diversion which the insurrection of Great Poland operated in his favour, when Kosciusko saw advancing against him the Russian armies under Suworoff and Fersen. It was in vain that he attempted to prevent the junction of these two armies. On the 4th of October, being attacked at Maciejowice by very superior forces, he held his ground during the whole day; but at length he sank down pierced with wounds, exclaiming, as he fell, Finis Poloniae. As soon as he was sufficiently recovered, he was sent to St Petersburg, where he remained a prisoner of state for two years, and was only liberated on the accession of the Emperor Paul. He immediately set out for England, and thence for America, where he passed several years amongst his old companions in arms. In 1798 he returned to France, where he was received with much distinction, and learned that a great number of his countrymen had enlisted under the banners of the new republic. Those who served in the army of Italy sent him the sabre of John Sobieski, which had been found in the Casa di Loretto. From this time he lived either at Paris or at a country-house which he had purchased near Fontainebleau. When Napoleon was about to invade Poland in 1807, he wished to avail himself of the name of Kosciusko, in the hope of thereby inducing the people of that country to revolt against the Russians. But the Polish general had too much knowledge and experience not to divine the object for which recourse had been had to him, and positively refused. The address, signed with his name, which appeared in the Moniteur in 1806, was a forgery, and was everywhere accepted as such, though it was not till eight years later that Kosciusko was able to give it a public and formal denial. When the Russians penetrated into Champagne in 1814, they learned with surprise that their ancient enemy was living peaceably there. All those who had an opportunity of visiting his retreat testified their regard for him in the strongest manner; and the Emperor Alexander himself had a long interview with the veteran patriot. Nothing could induce Kosciusko to return to his native country. In 1815 he made a tour in Italy, and afterwards established himself at Soleure in Switzerland, where he devoted himself chiefly to agricultural pursuits. His death, which took place on the 16th of October 1817, was occasioned immediately by an accidental fall from his horse. On the news of his demise, the whole of Europe resounded with his praises; amongst all nations, and in every country, justice was equally rendered to the brave soldier and the true patriot, who, without any other object than the independence and welfare of his country, had exposed himself to the greatest perils, and the most painful sacrifices. His remains were interred in the cathedral at Cracow, between those of John Sobieski and of Joseph Poniatowski.

KÖSFEILD, KOESFELD, or COESFELD, a town of Prussia, capital of a cognominal circle in the government of Munster, on the Berkel, 20 miles W. of Munster. It is surrounded by old walls, and has a castle, with some manufactures of linen and woollen goods. Pop. (1849) 3607.

KÖSLIN, or KOSSLIN, a town of Prussia, capital of a cognominal government in the province of Pomerania, on the Niesebecke, about 4 miles from its mouth, in the Jam-lagoon, which communicates with the Baltic. The town was rebuilt on a regular plan, after its destruction by fire in 1718, by Frederick William I., to whom a statue has been erected by the citizens in the market-place. Köslin is the seat of the superior courts of the government, and has a gymnasium, normal school, a society for the promotion of agriculture, &c. Chief manufactures, linens, woollers, hosiery, and leather. On the Gollenberg, a little to the E. of the town, is a monument to those Pomeranians who fell in the campaigns of 1813-15. Pop. (1849) 8813.