Prussian Silesia, the S. E. province of Prussia, bounded N. by Brandenburg and Posen, E. by Russian Poland and Austrian Galicia, S. by Austrian Silesia and Moravia, and S. W. and W. by Bohemia, the kingdom of Saxony, and the Prussian province of Saxonv; area 15,556 sq. m.; pop. in 1871, 3,707,167, of whom 1,760,-341 belonged to the Evangelical church, 1,896,-136 were Roman Catholics, and 46,629 Jews. It is divided into the districts of Breslau, Lieg-nitz, and Oppeln. It is separated from the Austrian dominions by the Sudetic chain of mountains, which consist of long well wooded ridges with isolated peaks. There are two principal groups, the Riesengebirge in the N. W. part of the range and the Glatz mountains in the opposite direction; the most elevated peak of the former, the Schneekoppe, is upward of 5,000 ft. high, and of the latter, the Great Schneeberg, nearly 5,000 ft. There are fertile valleys of considerable extent. The Oder flows through the province in a general N. W. direction, and divides it into two nearly equal portions, that on the left of the river being mountainous, and that on the right flat.

This level portion is sandy, with extensive tracts of heath and stagnant pools. A small portion of the S. E. corner is drained by the upper course of the Vistula. The mineral wealth of Silesia is confined principally to the upper or S. E. part of the province. Gold and silver are procured in small quantities; copper, lead, and zinc are found; and coal and iron are abundant. Quarries of limestone, marble, and sandstone are worked. Large numbers of cattle and sheep are raised, the wool of Silesia being of superior quality, and forming next to linen the chief export. The principal manufactures are of linen, cotton, and woollens, iron, paper, leather, glass, porcelain, castings, and sheet iron. Among the principal towns, besides Breslau, the capital, are Glogau, Liegnitz, Oppeln, and the fortresses Schweid-nitz, Neisse, Glatz, and Kosel. - Silesia became subject to Poland in the 10th century, and in 1163 it was ruled by three independent Polish princes. It was afterward subdivided into numerous petty states, which in detail became tributary to the king of Bohemia, and fell to Austria in 1526. The claims of Frederick the Great upon the former duchies of Liegnitz, Brieg, Wohlau, and Jagerndorf, founded on an old treaty of inheritance, gave rise to three wars for the possession of Silesia, the first in the years 1740-'42, the second in 1744-'5, and the last in 1756-'63 (the seven years' war). By the treaty of Hubertsburg in 1763 the province was finally secured to Prussia, except the part now known as Austrian Silesia. A part of Lusatia was added to it by the treaties of 1815.