The Museum of the Posavje Region in Brežice originated before World War II from the private collection of archaeology enthusiast Otto Aumann of Krško where it was stored in the Church of the Holy Spirit. In 1949 artist Franjo Stiplovšek, assisted by curator and archaeologist Rudolf Bratanič, moved the collection from Krško to the Brežice Castle, one of the most representative castles in Slovenia. It has been carefully renovated since 2006 and hosts several collections, among them the 16th century peasant revolts and Reformation, and the recent history of the Posavje region.
In 1951 the exhibition of National Liberation Struggle (NOB) was added to the previous archaeological collection and exhibited in Knight's Hall. At the time, after World War II, the Brežice Castle was quite neglected because in 1848 the Attems family abandoned it and since then it had been used as an Austro-Hungarian army post, social housing, and offices. In 1917 an earthquake badly damaged some parts of the castle. Then World War II and the post-war period added to its miserable state. With the care for museum collection since 1949 also conservation and restoration works on the castle complex had to be carried out and space was eventually adapted to museum conditions.
The castle has been under a systematic yet phased reconstruction since 2006 and has turned into an impressive and welcoming venue. It is one of the biggest and picturesque museum spaces in Slovenia, with approx. 2000 square meters of exhibition space in 25 halls. With the collaboration of the National Museum of Slovenia museum experts organised and complemented the permanent exhibitions.
The Knight's Hall
The Knight's Hall from the 18th century displays the largest fresco painted hall with a secular narrative in Slovenia. It is believed to be painted by Frančišek Karl Remb, courtly painter of the Attems family which were the wealthiest nobles in the 18th century and possessed almost all the major castles and palaces in Styria and Lower Savinjska Region (Podčetrtek, Štatenberg, Dornava pri Ptuju ...).
Every summer Seviqc Brežice Festival international old music festival takes place at the Knight's Hall being the main location for these well-attended concerts.
The Museum of the Posavje Region is divided into several exhibition sections:
- the archaeological exhibition presents the cultural heritage of Posavje from the end of the Stone Age to the settlement of ancestors and the shaping of feudal society in the Early Middle Ages;
- the ethnological exhibition presents the life and creativity of the domestic population in the 19th and 20th centuries (agriculture, stock-breeding, furnishing homes, forging, wickerwork, honey pastry, pottery, spinning, weaving, and viticulture);
- the medieval collection with arms, armours, and cannons from 16th and 17th century, when Brežice Castle was one of the important strongholds against the invasions of the Turks;
- the Peasant Revolts and the Reformation exhibition presents both, the Slovene peasants' revolt in 1515 and the big Slovene - Croatian revolt in 1573, its leaders (Matija Gubec, Ilija Gregorič) demands and consequences. The Reformation period had a big impact on Slovene language and national awareness and the exhibits include also a precious Dalmatin Bible (the first complete Bible translation from German into Slovenian, by Jurij Dalmatin) dating from 1584;
- the musical instrument collection features a square piano made in Ulm around 1770;
- the recent history collection presents the events of the 19th and 20th centuries in Posavje, and the city lifestyle (the Bürger - Burgher - Bourgeois and ''Under Nine Flags; the Posavje 1900–1990 exhibitions);
- the art history collection features Baroque paintings, sculptures, and arts and crafts products. The illusionist frescoes of the castle interiors are definitely one of the best examples of what the rich Maecenas such as the Attems family could afford in the 18th century, painters working in Brežice Castle covered all major secular and church orders in the region of nowadays Slovenia, north Croatia, and Austrian Styria and those were: Franz Ignaz Flurer, Karl Franciscus Remb, Valentin Metzinger, and Franc Jelovšek. Recently the exhibition of Alenka Gerlovič's (1919–2010) works has been opened as well;
- the Stiplovšek Memorial Room honours the memory of painter and graphic artist Franjo Stiplovšek (1898–1963), presenting a collection of his expressionist woodcuts from the 1920s, genre paintings, portraits, landscapes, and still-life paintings.
The Museum of the Posavje Region also organises temporary exhibitions in collaboration with four other museums in the neighbouring regions, the Bela krajina Museum, Metlika, the Dolenjska Museum Novo mesto, the Božidar Jakac Gallery, Kostanjevica na Krki, and the Kočevje Regional Museum.