The House of Hohenzollern-Sigmaringen is the senior Swabian branch of the House of Hohenzollern. The branch ruled the Swabian County of Hohenzollern-Sigmaringen, which in 1623 became a principality. The small sovereign state with the capital city of Sigmaringen was annexed to the Kingdom of Prussia in 1850 following the abdication of its sovereign in the wake of the revolutions of 1848, then became part of the newly created Province of Hohenzollern.