The colonnade frieze has three sculpted medallions with the portraits of (probably) Charles V, his wife Isabella of Portugal and their son Philip II of Spain, who stayed here at several occasions.

[1] It was probably here that Alexander Farnese, Duke of Parma and Governor of the Netherlands, signed the declaration that made William the Silent, leader of the Dutch Revolt, an outlaw.

The rest of the building was restored by Victor de Stuers and presented to the city of Maastricht in order to house a local history museum (which did not happen until recently).

In 1954, the wealthy The Hague couple Frederik Wagner and Ambrosina de Wit bequeathed their art collection to a foundation based in the city of Maastricht.

The pavilion room in the courtyard was specifically built to house valuable boiseries from a demolished 18th-century Maastricht mansion.

The renovation included a partial restoration of the originally largely blind facade of the Spanish Government building.

The museum re-opened in March 2012 with some rooms dedicated to important figures from Maastricht history, e.g. the emperor Charles V, the printer Jean-Edmé Dufour, the architect Mathias Soiron, the entrepreneur Petrus Regout and the draughtsman Philippe van Gulpen.

The collection, brought together by the artistic couple, contained art and artifacts from a wide array of periods and regions, some of which has been discarded by the current directors.

The Wagner-De Wit collection also included sculpture from the Middle Ages and Renaissance period, tapestries and furniture from the 16th, 17th and 18th centuries, glass and crystal objects, antique coins, and artifacts from the Far East.