The Museum of Trenčín is a cultural and scientific institution with a 120-year old history. Its predecessor was The Natural Scientific Alliance of Trenčín County, established in 1877. After merging with the Museal Society in 1912, the Trenčín Museum was established. Its first chairman became Karol Brančík, a county doctor and enthomologist with an international reputation.
Apart from its main edifice at the Peace Square (the so-called County House), the Museum of Trenčín supersedes the castle with several expositions, as well as the Charnel House of St. Michael, the Executioner´s House and many other expositions and properties outside Trenčín. The subsidiary in Nové Mesto nad Váhom has an exposition named From The History of Nové Mesto and Surroundings. The exposition at The Mansion Ambrovec in Beckov is dedicated to the history of this township, as well as to the Tatrín Union along with a distinguished national rioter Jozef Miloslav Hurban. The exposition in Čachtice presents the history of the village and also a famous "Bloody Countess" Elizabeth Bathory.
The strategical position of Trenčín near the river Váh´s fords and Carpathian passes was recognised even by the old Romans, made evident by a renowned Roman inscription on the castle rock in Trenčín. The representative of the Auxiliary Legion II, Marcus Valerius Maximianus, let this inscription be chiselled into the rock in 179 A.D. to commemorate the victory of Caesar Marcus Aurelius and his son Commodus.
As a part of the region with rich history and culture, the Museum of Trenčín is engaged in the history of Trenčín and its surroundings, which is why the exposition is named From the History And Culture of Privileged Trenčín Town and Quondam Trenčín County (opened in the County House at the Peace Square N° 46 in Trenčín).
Trenčín itself arose as a commercial settlement under the mighty castle in the 12th century. In 1412 it was privileged to become the independent royal town. Nowadays it is the city of the region and the domicile of the regional authorities of the state administration.
For a period of nearly 700 years it has been used as a function of administrative, commercial and cultural centre of the Middle Váh Valley. It is the centre of Trenčín’s self-governing region.