Prince Karl (1785–1853), the son of Anton Aloys, ruled from 1831 until 1848. In 1833 Karl called a constitutional assembly (German: "Landtag") together and created a constitutional charter that would be the law in his lands. He founded a hospital for his subjects, and had the "Ständehaus" built on the modern "Leopoldsplatz" in Sigmaringen (today owned by the Hohenzollerischen Landesbank). Karl also removed the burden of serfdom and various other medieval laws. In recognition of Karl's efforts to improve the lives of his subjects, in 1857 the hospital that he built was renamed the "Fürst-Carl-Landesspital" (Prince Carl Regional Hospital). In 1869 Karl Anton, following the death of Konstantin the last prince of Hohenzollern-Hechingen, annexed the lands of Hohenzollern-Hechingen and became the prince of Hohenzollern.