In January 1981, the Stadtmuseum Ingolstadt (Municipal Museum Ingolstadt) was reopened after it had moved out of the New Palace in 1965.
At that time, the rich collections disappeared in storage rooms. It took 15 years until Ingolstadt received a new city museum. The Kavalier Hepp Fortress, which is itself a monument of Ingolstadt’s history, was found to be an excellent building for a museum. It also houses the Stadtarchiv (municipal archive) and the Wissenschaftliche Stadtbibliothek (Scientific Library).
The Cavalier Hepp Fortress was built between 1838 and 1843. It was named after Major Kaspar von Hepp (1758–1806). The cavaliers lost their importance as early as in 1875, when the outer belts of the fortress were built.
The history of the Stadtmuseum is closely linked to that of the Historischer Verein, which was founded in 1865. In addition to the maintenance of the historical knowledge about Ingolstadt and its surroundings through lectures and publications, the association saw its duty in collecting objects of historical importance. The collection was initially distributed between the town hall and the mediaeval Kreuztor. The governor of the fortress of Ingolstadt, his Excellency Karl von Sauer (1834–1911), suggested the foundation of the museum.
In 1904, the city provided a space, but it was linked to the condition that the association made its collection the city’s property as the basis for a museum.
In 1905, the museum was established in the old university building, the Hohe Schule, and in 1906 it was expanded. In 1907, the first “Führer durch das Stadtmuseum Ingolstadt” (Guide through the Municipal Museum Ingolstadt) was published. The main attractions were the Swedish grey horse, i.e. King Gustav Adolf’s horse from Sweden, and the Privilegienbuch (Book of Privileges). In 1925, the municipal archive, library and the museum moved to the New Palace, which was bombed in 1945 but subsequently rebuilt. When the city council decided in 1973 to renovate the Cavalier Hepp Fortress, the fortress was in a very poor condition. After the war, it had been used as emergency housing. With the completion of reconstruction and renovation work done, it became clear that the building is very well suited for a museum.