 On 25 January 1805, Charles was granted the title "Landgrave of Hesse" by his elder brother, who had assumed the higher dignity and titulary of Imperial Prince-Elector.In 1807, the manor and village of Gereby by the Schlei near Kappeln in Schwansen was renamed Carlsburg in honour of Prince Charles.Charles had purchased the property of Gereby in 1785, where he abolished serfdom in 1790.