the first prince (German: Fürst) of Hohenzollern-Sigmaringen. During the Thirty Years' War, the castle was besieged by Swedish troops in 1632, and retaken by the Imperial troops in the following year. During the attack by Imperial troops under General Horn, the eastern section of the castle was destroyed by fire. Before the siege, Johann fled to Bavaria. He would remain in Bavaria until his death, at age 60, in 1638. Johann's son, Meinrad I (1605–1681), was the prince from 1638 until 1681. Meinrad had the burned eastern wing rebuilt during 1658 and 1659 by the master builder Michael Beer. Both eastern buildings, built when the Werdenberg family owned Sigmaringen, were combined under a single roof. Maximilian (1636–1689), son of Meinrad I, was prince of Hohenzollern-Sigmaringen from 1681 until 1689. His son Meinrad II (1673–1715) ruled from 1689 until 1715. From 1698 on he ruled in Haigerloch. His son, Josef (1702–1769) ruled from 1715 until 1769. In 1724 Josef ordered the construction of the Marstalles or royal stables. In addition to this construction, in 1736 he had the castle modernized and the Knights' Hall (German: Rittersaal) was built. In 1867 it was refurnished and renamed the Ancestors' Hall (German: Ahnensaal). His son, Karl Friedrich reigned from 1769 until 1785. Karl Friedrich's son, Anton Aloys (1762–1831), reigned from 1785 until 1831. Between 1815 and 1817 he had the granary rebuilt as a five-story knights' building, which became known as Wilhelm's building (German: Wilhelmsbau). 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. During the German Revolution of 1848 Karl abdicated in favor of his son, Karl Anton, on 27 August 1848. 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. A destination for the rich and powerful Karl Anton built the castle into a meeting point