Landgraviate of Hesse-Darmstadt
In 1600, Langen, along with the whole "Amt" of Kelsterbach was sold by the Counts of Isenburg to the Landgraviate of Hesse-Darmstadt. Langen has belonged to Hesse since then. With the partitioning of the Länger Mark in 1732, whose main estate Langen was, the community got two thirds of the land, and Egelsbach the other third.