The collection of arms is exhibited in the eastern section of the old ceremonial hall of the Romanesque Great Hall on the ground floor. This rich collection, which comprises over 500 piecees of edged weapons and firearms, was established by merging the collection of the Ptuj Museum Society and that of the Herberstein family. Most of the exhibited material originates from nearby Vurberk castle. In spite of the important military role Ptuj Castle had for centuries, none of its arms were preserved. Research, however, proved that the castle's arms were at first kept in the Romanesque fortified tower which stood in the centre of the castle's inner courtyard. The fortified tower was demolished in the latter half of the 17th century and the arms were moved to the room in which they are now exhibited.
The old arms allow us to trace the development of types of weapons and fighting techniques, and some objects are real masterpieces of craftsmanship. The collection was installed to create the ambience of a real castle arsenal. Among the bladed weapons are some interesting, superbly decorated, halberds and specimens of the ťTurkish spoilsŤ which Christian soldiers took as trophies from their ťhereditaryŤ enemies. The exhibition illustrates the development of firearms from the late 14th century to the early 20th century.
The collection's artillery pieces are of major importance. Further exceptional items are the armours of the province's mercenaries from around 1600 and a good-quality copy of the ceremonial armour of the Visconti Dukes of Milan. Worth attention also are the bladed weapons and firearms copied from Oriental models.