The Old Masters Picture Gallery inside Schloss Wilhelmshöhe palace is one of the most important collections of its kind and is internationally renowned. Its history, which spans more than 500 years, goes back to the times of the landgraves and their collections.

The exhibition on its three floors provides an excellent overview of European painting from the late Gothic period to Classicism, with a particular focus on 17th century Dutch and Flemish art, including numerous masterpieces by Rubens, Frans Hals, Van Dyck and Jordaens. Its collection of works by Rembrandt, among these the famous paintings "Jacob Blessing the Sons of Joseph" and his portrait of Saskia van Uylenburgh, is one of the most extensive anywhere in the world. The German, Italian, French and Spanish Old Masters are represented with works by Dürer, Titian, Poussin and Murillo, for example.

The picture gallery's origins date back to 1509, when Lucas Cranach the Elder created a small winged altar in memory of William II, Landgrave of Hesse. Most of the collection was acquired between 1748 and 1756, when William VIII, Landgrave of Hesse, commissioned his diplomats as well as professional art buyers to purchase approximately 800 paintings in the Netherlands, Paris, Brussels, Antwerp, Venice and Germany. Between 1749 and 1751, a dedicated building for the collection was constructed behind the landgrave's palace between Auehang and Frankfurter Strasse. In 1877, the paintings were moved to a newly erected building at Schöne Aussicht, now known as the Neue Galerie, where they remained until the Second World War began. The Old Masters Picture Gallery moved to Schloss Wilhelmshöhe palace in 1974.

Kassel's collection of antiquities on the ground and lower ground floors of Schloss Wilhelmshöhe palace offers a fascinating insight into the ancient Mediterranean cultures. The around 800 exhibited objects from the Bronze Age to Greece's golden age and that of the Imperium Romanum provide an overview over how the arts evolved in the various ancient civilisations. They bear witness to the landgraves' passion for collecting and illustrate Kassel's keen interest in antiquities. Starting with "Antiquity Brought to Life", the tour culminates in "250 Years of Collecting Antiquities" via "The Landgraves' Legacy".

In the main hall ("Antiquity Brought to Life"), the exhibition on culture in the everyday lives of the ROMANS is dominated by busts of emperors and other important personages. Exhibits found in various locations, for example in the course of a Kassel-led excavation on Samos, are on display in the space dedicated to ARCHAEOLOGY. Numerous marble SCULPTURES give the visitors an impression of the beauty of the sculptures created in antiquity. Vases often depict symposiums, athletic contests and plays, thereby giving us a glimpse of what everyday life was like in ANCIENT GREECE. One of the subjects all of the civilisations of antiquity have in common is MYTHOLOGY, whose diversity is portrayed in a particularly illustrative way by the images on the vases. The "Rome Hall" was designed especially for its purpose and focuses on the history of the collection.

The 30 large-scale historic cork models which Frederick II, Landgrave of Hesse-Kassel purchased in Rome at the end of the 18th century are on show on the lower ground floor. It is one of the most extensive collections of such models anywhere in the world.