Flensborg, a Prussian town of Schleswig-Holstein, and one of the most important towns of the district. It is situated on a fjord of the same name, about 20 miles N.E. of Schleswig. It possesses tobacco, soap, and rice manufactures, foundries, breweries, distilleries, and sugar refineries, palm-oil mills, and steam bakeries; and it has a considerable West Indian trade. The town, with the rest of the duchy, became Prussian in 1866.