The Grand Duchy of Hesse (German: Großherzogtum Hessen) was a former state that existed in modern-day Germany. It was formed in 1806 after the dissolution of the Holy Roman Empire as a result of the actions of Napoleon, who then elevated the former Landgraviate of Hesse-Darmstadt to the level of grand duchy. For this reason, this state was occasionally known simply as Hesse-Darmstadt.