Sønderborg

Sønderborg , Ger. Sonderburg, city (1992 pop. 25,551), Sønderjylland co., S Denmark, on both sides of the Als Sund. The older section of the city is situated on Als Island and is connected by bridge with the newer quarter on Jylland. Sønderborg is a port, an industrial and commercial center, and a seaside resort. Manufactures include textiles, machinery, furniture, chemicals, and beer. The city developed around a 13th-century castle and was part of the duchy of Schleswig. After his deposition, Christian II was held prisoner there from 1532 to 1549. Christian III (reigned 1534-59) created the duchy of Sønderborg for his younger son John, from which the branch of Schleswig-Holstein-Sønderborg-Glücksburg (which has occupied the Danish throne since 1863) is descended. The city was held by Prussia from 1864 to 1920.