Günther Victor was the final sovereign prince of Schwarzburg-Rudolstadt and Schwarzburg-Sondershausen.

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, the family split in the 16th century into the lines of Schwarzburg-Sondershausen and Schwarzburg-Rudolstadt, with the Sondershausen dying out in 1909.