The King's brother: Karl II. August of Palatine-Zweibrücken, Portrait in: Johann Nepomuk Anton von Leuthner: Diätetische Pastoral-Arzneykunde für Seelsorger. Nuremberg, 1782

Karl II. August of Palatine-Zweibrücken (1746–1795) was the older brother of Bavaria's first King Maximilian Joseph (1756–1825). Both descended from the Palatine-Birkenfeld-Bischweiler line. In the year 1775, Karl August suceeded his uncle as Duke of Palatine-Zweibrücken. The Duchy was located on the left bank of Rhine river, close to the French border and also disposed of possessions in Alsace.
The capital was Zweibrücken. On top of the Karlsberg at Homburg, Karl August had built a magnificent castle which became his residence in 1779. The imposing complex was supposed to incorporate his manifold collections which included not only books and paintings, but also graphics and a natural history collection.
At the same time, the castle mirrored the duke's self-comception as an absolutistic monarch.