Hermann I (died 25 April 1217), Landgrave of Thuringia and (as Hermann III) Count Palatine of Saxony, called the Hard, was the second son of Louis II, Landgrave of Thuringia (the Iron), and Judith of Hohenstaufen, the sister of Emperor Frederick Barbarossa.
Life
Little is known of his early years, but in 1180 Hermann joined a coalition against Henry the Lion, Duke of Saxony, and with his brother, Louis III, Landgrave of Thuringia, suffered a short imprisonment after his defeat by Henry at Weissensee. The brothers were released the following year. Louis had been made Count Palatine of Saxony as a reward for his services to the emperor, but transferred the dignity to Hermann. He strengthened his authority over the County Palatine by marrying Sophia, daughter of Lutgard of Stade and Frederick II of Sommerschenburg, a former Count Palatine.
Louis III died in 1190. Emperor Henry VI attempted to seize Thuringia as a vacant fief of the Holy Roman Empire, but Hermann frustrated the plan and established himself as the landgrave. Having joined a league against the emperor, he was accused, probably wrongly, of an attempt to murder him. Henry VI was not only successful in detaching Hermann from the hostile combination, but gained his support for the scheme to unite Sicily with the Empire.
Hermann joined the German Crusade of 1197 but returned on news of Henry VI's death.