The principality joined the Confederation of the Rhine in 1806 and was a member state of the German Confederation between 1815 and 1850. The democratic Revolution of 1848 was relatively successful in Hohenzollern, and on 16 May 1848, the Prince was forced to accept the constitution limiting his power. However, the conflict between monarch and democrats continued, and on 6 August, Hohenzollern was occupied by Prussian forces. On 7 December, 1849, Prince Friedrich Wilhelm Konstantin sold the country to his relative, King Frederick William IV of Prussia. On 12 March 1850, Hohenzollern-Hechingen officially became part of Prussia. Hohenzollern-Hechingen and Hohenzollern-Sigmaringen, which also became part of Prussia in 1850, were called the Hohenzollernsche Lande .