The Grand Duke of Hesse was a title held by the rulers of the Grand Duchy of Hesse, a historical state in Germany. This title was established in 1806 when the Landgrave of Hesse-Darmstadt was elevated to grand duke status. The Grand Duchy was part of the German Empire until the end of World War I in 1918, when monarchies were abolished. The last Grand Duke of Hesse was Ernst Ludwig, who reigned from 1892 until his abdication in 1918. The grand ducal family played a significant role in European history, with connections to various royal families, including the House of Hesse and the British royal family.