The Landgraviate Castle of Butzbach was originally a town castle of the Lords of Falkenstein.
However, today’s excavations in the castle area have revealed that there was probably a small ring-shaped moated castle on the site as early as around 1200. The Falkensteins extended the estate around 1390, then it was the seat of the family of Eppstein-Königstein, the archbishop of Mainz, and finally a castle of the landgraves of Hesse. Landgrave Philipp von Hessen-Butzbach (1609-1643) rebuilt the castle, which had been partially burned down in 1603, as a stately residence, incorporating a late medieval core building.
The castle had an observatory. Thus, in 1621 and 1627, the astronomer Johannes Kepler was a guest here twice. In 1898, the castle was transformed into an infantry barracks and was named Castle Barracks. The landgravial castle was originally a two-winged building, the west wing was only built with an extensive barracks extension in 1935/36. From 1951 to 1992, the barracks were used by the United States Army. After the withdrawal of the troops, the castle is used for civilian purposes.
RIEDEL Networks uses 2 floors in the west wing and another floor in the south wing of the Landgrafenschloss.