The Grand Duke of Hesse was a title held by the ruler of the Grand Duchy of Hesse, a historical state in Germany. This title was established in 1806 and lasted until the end of the German monarchy in 1918. The Grand Duchy was known for its rich cultural heritage and economic development, particularly in the areas of textiles and manufacturing. The most notable Grand Duke was Louis IV, who reigned from 1877 to 1892. He was known for his progressive policies and efforts to modernize the state. The Grand Duchy eventually became part of the Weimar Republic after World War I, leading to the abolition of the monarchy.