The royal seat contains the oldest past of the fortress ruins. It conceals the remains of the 12th century knights' castle. Between 1553 and 1554, Duke Christoph von Württemberg had the mediaeval castle extended to create a larger palace complex.
The remains of the palace.
The royal seat comprises a three-winged palace complex enclosed by a wall on the fourth side. The only remains of the knights' castle are in this wall, the south wing and the main walls and the two other wings. They consisted of a building measuring 11 x 22 meters and a courtyard. Their precise age is not known. However, the walls that remain are certainly not from the time of the legendary 10th century Swabian Duke Burkhard.
According to the keystone, the palace was completed in 1554.
The expansion of Hohentwiel to create a regional fortress dates back to Duke Ulrich von Württemberg, who fled to Hohentwiel in 1519. However, it was only under his son, Duke Christoph, that the royal seat got its final design. Master builder Aberlin Tretsch (1500–1577), who from 1553 built the three-story arcades around the old palace courtyard in Stuttgart, also built the royal seat on Hohentwiel at the same time. The year 1554 seen on the vault keystone of the north gate bears witness to this.
Next to the barrel vaults on the north gate, the kitchen is the best preserved part of the building. The thick walls which enclosed the courtyard, a cistern, remains of a round tower on the north-east corner, and window casings with shallow arches above the window openings are all that remain to be seen of Aberlin Tretsch's's palace architecture
The upper fortress provides different effects from every angle.
