Posen, a province of Prussia and, its capital. The former is bounded N. by Prussia, E. by Russian Poland, S. by Silesia, and W. by Brandenburg, and has an area of 11,180 square miles. Some portions are very fertile, producing wheat and other cereals, potatoes, hops, tobacco, and even wine, whilst the wild pastures feed many cattle and sheep. The rivers Netze, Warthe, and Obra drain into the Oder, and the Vistula bounds the N.E. frontier. Originally a district of Poland, it was acquired by Prussia in 1772 and 1793, and the treaty of 1815 confirmed the annexation. Posen, the capital, stands at the junction of the Cybina and the Warthe, and is strongly fortified. Its foundation dates back to the 10th century. It is the seat of a Roman Catholic archbishopric, and the cathedral contains several curious specimens of ancient art. Agriculture is the chief source of prosperity.