Over a period of almost fifty years, Wilhelm Hack had placed emphasis on different fields in his collection. These are the three major components:
-The “Gondorfer Fund” derives from an excavation of tombs from the Migration Period in Gondorf at the river Mosel and includes Celtic, Roman, and Franconian grave furnishings from the 5th century BC to the 8th century AD.
- The medieval religious art comprises metal and ivory works, book and glass painting, and, above all, sculptures and panel painting of an extraordinary quality.
- The museum's supra-regional importance is, however, due to the third group of artworks from the 20th century: the collection of modernism documents the development of non-representational art from its beginnings around 1910 to the present.