Principality of Schwarzburg-Sonderhausen

The House of Schwarzburg was one of the oldest noble families of Thuringia, which is in modern-day central Germany. Upon the death of Prince Friedrich Günther in 1971, a claim to the headship of the house passed under Semi-Salic primogeniture to his elder sister, Princess Marie Antoinette of Schwarzburg who married Friedrich Magnus V, Count of Solms-Wildenfels. Reigning over the County of Schwarzburg and founded by Sizzo I of Schwarzburg (died 1160), the family split in the 16th century into the lines of Schwarzburg-Sondershausen and Schwarzburg-Rudolstadt, with the Sondershausen line dying out in 1909.