Giessen came into being as a moated castle in 1152 built by Count Wilhelm von Gleiberg, although the history of the community in the northeast and in today's suburb called "Wieseck" dates back to 775. The town became part of Hesse-Marburg in 1567, passing to Hesse-Darmstadt in 1604. The University of Giessen was founded in 1607. Giessen was included within the Grand Duchy of Hesse created in 1806 during the Napoleonic Wars. After the First World War, it was part of the People's State of Hesse.