Altenburg(redirected from Altenbourg)Altenburg(äl`tənbo͝ork), city (1994 pop. 46,650), Thuringia, E Germany, on the Pleisse River. Manufactures include sewing machines, apparel, and cigars. Lignite is mined nearby. "Skat," the popular German card game, originated there in the 19th cent. Built on the site of early 9th-century Slavic fortifications, Altenburg became an important trade center and was made an imperial city in the 12th cent. It formally passed in 1329 to the house of Wettin and later was (1603–72, 1826–1918) the capital of the duchy of Saxe-AltenburgSaxe-Altenburg, Ger. Sachsen-Altenburg, former duchy, Thuringia, central Germany. Altenburg was the capital. Created a separate duchy in 1603, it was ruled by an Ernestine line of the house of Wettin...... Click the link for more information. . Noteworthy structures include an 11th-century church and the tower of the monastery founded (1172) by Emperor Frederick I.