In 1606 Elector Friedrich IV of the Palatinate had a town fortress with a citadel, the "Friedrichsburg", erected out of the village "Mannenheim". Following the destruction of the Thirty Years' War, the town was rebuilt under Elector Karl Wilhelm I. Trade and commerce privileges, the erection of a church and, around 1664, a simple palace increased Mannheim's importance.
Numerous plans for providing Mannheim, which was seriously damaged during the Palatinate War of Succession, with a representative palace complex were never carried out. It was not until 1720 that one of the largest absolutist palaces on the Upper Rhine was built under Elector Carl Philipp according to the design of Louis Remy de la Fosse. Following continuing conflicts with Protestants, the Catholic imperial prince moved his residential palace from Heidelberg to Mannheim.
The absolutist, palace complex in the style of the late Baroque has a 440 meter (1,445 feet) long representative façade structured by an accentuating Middle Building (Corps de logis - main building) and the East and West wings. In addition to these buildings, the palace also encompassed numerous other structures for the royal retinue, the administration and the judiciary. The Palace Church (Schlosskirche) and the Jesuit Theological College (Jesuitenkolleg) completed the residence. In the western wing of the palace the electoral Court Opera (Hofoper) and Ball House (Ballhaus) were constructed in 1737 and 1742 under the theater architect Allesandro Galli da Bibiena.
Following Carl Philipp's death in January 1742, his only male blood relative, the 18 year old Carl Theodor, assumed the electorship and government of his uncle. Under his reign the Mannheim Court experienced a short, intense heyday. Art and science flourished at the "Musenhof" (Court of Muses). The Elector and his wife Elisabeth Augusta supported manufactories and promoted new institutions for the care of agriculture. In particular, music and theater also experienced intensive support and reached a very high level. Above all, Carl Theodor's interest in the German language and German theater led to the founding of the National Theater in 1778.
Historians and scientists researched and taught at their own academies, were they practiced national history, archeology, physics and astronomy. Additional fields of activity included land surveying meteorology and natural science collections. The cabinet of copperplate engravings and drawings, the electoral painting collection and the Academy of Drawing and Sculpture (Zeichnungs- und Bildhauerakademie) promoted not only the consideration of art, but also many artistic talents.
Construction work was conducted on the palace for nearly forty years. Under the renowned architect Guillaume d´Hauberat an elegant decoration of the interior rooms was achieved in the late 1720s that reflected the latest French taste. This was in contrast to the exterior of Mannheim Palace, which had been received with great criticism.
The Middle Building houses a dual staircase, which is one of the largest in German palace architecture. This important attribute of the demonstration of royal power served not only as a symbol of the sovereign's understanding of art, but also for the presentation of the royal retinue and the reception of guests.
The main landing of the magnificent staircase formed the hallway before the Hall of Knights (Rittersaal), the main representation room of the palace. In the two-story hall there are (reconstructed) stuccowork decorations by Egell and a fresco by Cosmas Damian Asam with motifs from antique mythology. In addition, it also houses the gallery of ancestral portraits of the Palatinate-Neuburg dynasty, which had died out with Carl Philipp, as well as oversized marble statues of Carl Theodor and Elisabeth Augusta by Peter Anton Verschaffelt
Today the former first antechamber of the Elector in the "Electoral Quarters" has been reconstructed. This so-called trabant room is characterized by rich ornamental plasterwork with mythological scenes and precious Gobelins.
The most attractive room of the palace, and the only one in original condition, is the private library of Electress Elisabeth Augusta. The so-called "Cabinet Library" (Kabinettbibliothek) was designed in 1755 by Nicolas de Pigage. This intimate refuge with portrayals of muses, eroticism and allegories exudes a cheerful, sensuous atmosphere.
The Palace Church follows its example - the Main Church of the Jesuit Order in Rome. It rises up at a prominent location at the entrance to the Court of Honor (Ehrenhof) and was built between 1733 and 1760 under Carl Philipp and Carl Theodor following the palace complex. The Court Church (Hofkirche) was to serve as a house of God, a representation building and at the same time as the tomb of the electors. Numerous renowned artists such as Bibiena, d´Hauberat, Pigage, Egell and Verschaffelt worked on the building. With its rich appointments, it is one of the most important Baroque churches in Southwestern Germany.
Upon the death of the Bavarian Elector Max Joseph III on 12/31/1777, Carl Theodor succeeded him and moved his residence to Munich. There his politics was met with criticism at the Munich Court. Mannheim now developed to a trade and economic center with a middle-class character, and its palace never achieved its former importance again.
In the course of the Napoleonic reorganization, Mannheim fell to Baden in 1803 and became the palace of the Grand Duke. Industrialization and transportation did not stop even before the palace's immediate surrounding area, and a large part of the palace park was destroyed by the new train line. The hereditary grand duke and duchess of Baden, Karl von Baden and Stephanie de Beauharnais, Napoleon's adopted daughter, lived in the palace from 1806 to 1811. During this time several apartments and chambers were renovated, decorated with Gobelins and furnished in the style of Classicism.
Following Stephanie's death in 1860 the royal household in Mannheim was disbanded, and the Court of the Grand Duke in Karlsruhe only required chambers in the Corps de logis. The palace was partially used as a school for girls and the burned-out Opera was torn down. In its place the district court was erected. Administrative government offices and apartments for government officials were set up in the former residential palace. In 1919 Mannheim Palace became the property of the Free State (Freistaat) of Baden. The town presented its collections in the palace museum here beginning in 1926.
In World War II Mannheim Palace was almost completely destroyed. Only the Library Cabinet (Bibliothekskabinett) remained untouched as the only room of over 500. In 1947 the decision was made to rebuild the outer structure of the palace according to the historical model with the exception of the roof. On the inside the original layout of the rooms was completely changed, and only the Palace Church, the staircase and the Hall of Knights were restored. The Tax Office, the regional superior Court and parts of the university moved into the palace.