THORN, a strongly fortified town in the province of West Prussia, on the right bank of the Vistula (here spanned by a viaduct 1,100 yards long), 31 miles E. S. E. of Bromberg. Founded by the Teutonic order in 1231, and a member of the Hanseatic League, Thorn contains a town hall and a number of other buildings remarkable for their beautiful gables and interiors; became a Polish town in 1454; and was annexed to Prussia in 1793, and again finally in 1815. It became an important fortified stronghold in the 17th century: was five times besieged between 1629 and 1813; and since 1878 has been made a fortress of the first rank by Prussia, the old fortifications being removed, and a series of detached forts built. Copernicus was a native; and a colossal bronze statute of him was erected in 1853. An active trade in corn and timber is carried on. Pop. about 46,000.