He was born in Rudolstadt the second son of the reigning prince of Schwarzburg-Rudolstadt, Louis Frederick II and his wife Landgravine Caroline of Hesse-Homburg. His grandfather Friedrich Karl had died seven months before his birth and so he was born as heir apparent and Hereditary Prince. His father died on April 28, 1807 when he was fourteen so his mother acted as regent until he turned twenty one on November 6, 1814 when he assumed control of the principality. His reign spanning sixty years saw the creation of a Diet which he introduced in 1816 during the early years of his personal reign. When he ascended the throne in 1807, Schwarzburg-Rudolstadt was a member of the Confederation of the Rhine which was dissolved in 1813 with the Treaty of Paris on May 30, 1814 declaring the independence of the former Confederation states with Prince Friedrich Günther becoming the ruler of an independent principality. In 1815 the German Confederation was created and Schwarzburg-Rudolstadt along with other German monarchies joining. The last years of his reign saw the Austro-Prussian War of 1866 where Prince Friedrich Günther kept Schwarzburg-Rudolstadt neutral and following the conclusion of the war the creation of the North German Confederation. Following his death at Heidecksburg castle he was succeeded as prince by his brother Prince Albert as all of his sons by his first wife had predeceased him and his son by his second wife, Prince Sizzo of Leutenberg was born from a morganatic marriage.
He married and secondly Countess Helene of Reina on August 7, 1855 at Dresden. She was a daughter of Prince George Bernhard of Anhalt-Dessau in his second morganatic marriage, but she was adopted by her paternal uncle William on April 1, 1855 and assumed the title of "Princess of Anhalt"; however, this marriage was considered morganatic under the House Laws of the Schwarzburg family, and their children were created Prince and Princess of Leutenberg.
Princess Helene
Prince Sizzo
His third wife was Marie Schultze whom he married at Schwarzburg on September 24, 1861. This marriage was also morganatic and in 1864 he created the title Countess of Brockenburg for his wife. The marriage was childless. In addition with his legitimate issue, from his relationship with Friederike Thorwart he had three daughters, all of whom were legally accepted as offspring of Friedrich Macheleidt :
