Posen (Polish Poznan), a Prussian province, bounded N. by West Prussia, E. by Poland, S. by Silesia, and W. by Brandenburg. Area, 11,178 sq. m. The navigable Warthe traverses it from E. to W.; the Vistula touches it on the NE. The province belongs to the great plain of north Germany. Pop. (1900) 1,887,275, of whom 1,280,000 were Catholics, and 35,000 Jews. The great majority are of Polish stock, and speak Polish and its dialects. The chief towns are Posen (the capital), Gnesen, Brom-berg, Lissa, and Rawitsch. Posen formed part of Poland till 1772, when, at the first partition, the districts north of the Netze were given to Prussia; the rest was added in 1793. In 1807 Posen was included in the duchy of Warsaw; but in 1815 it was re-assigned to Prussia.
Posen, the capital, and a fortress of the first rank (1827-53), is situated on the Warthe, 158 miles by rail E. of Berlin. It became the seat of a Christian bishop in 968, and it was the capital of the early Polish dukes. In the 16th century it was an important trading mart, but by 1600 had begun to decline. The fortifications have been strengthened by detached forts built in 1876-84. The cathedral, a Gothic pile dating from 1775, has attached to it the 'Golden Chapel' of Count Raczynski. Other buildings are the town-house (1508), the Raczynski Palace, the Dzialynski Palace, the archiepiscopal palace, and a provincial museum of antiquities. The manufactures are artificial manures, agricultural implements, furniture, carriages, etc.; and there are breweries, distilleries, and flour-mills. Pop. (1875) 60,998; (1900) 117,033.