ALTENBURG, a town in Thuringia, Germany, formerly capital of the duchy of Saxe-Altenburg, 23m. south of Leipzig. Pop. From its ancient castle, on a lofty porphyry rock, Kunz von Kaufungen carried off, in the young princes Albert and Ernest, founders of the royal and ducal families of Saxony. Altenburg has local courts subordinate to those of Jena and a cathedral and various learned societies. There is also a museum, with natural history, archaeological and art collections, and among other buildings St. Bartholomew's church (1089) and the town hall (1562-64). There is considerable traffic in grain, horses and cattle of the surrounding districts. There are lignite mines in the vicinity. The town has foundries and machinery works. Hats, gloves, shoes, metal objects, brushes, musical in struments, paper and paper bags, cigars, playing cards and chemicals are made. The card-game of "Skat," universal in Ger many since 1835, originated among the peasantry here.