Burgruine Petersberg: A Medieval Castle Ruin in Friesach, Austria

Visitor Information

Google Rating: 4.7

Popularity: Low

Country: Austria

Civilization: Early Modern, Medieval European

Site type: Military

Remains: Castle

History

Burgruine Petersberg is a medieval castle ruin located in the town of Friesach, Austria. It was constructed by the Archbishops of Salzburg during the High Middle Ages and served as an important stronghold within the region.

The site first appears in written records in 860 when King Ludwig II of Germany granted a court in Friesach to Archbishop Adalwin of Salzburg. The castle itself was built around 1076 by Archbishop Gebhard of Salzburg amid the Investiture Controversy, a conflict between secular and ecclesiastical authorities. Its purpose was to control the strategic Alpine passes and restrict the movement of Emperor Henry IV, deliberately supporting Pope Gregory VII in this religious and political struggle.

Though the surrounding lands were governed by the Bishop of Gurk and the Dukes of Carinthia, the castle remained the property of the Archbishopric of Salzburg. This ownership was fiercely defended, as seen when the fortress repelled an assault by Duke Engelbert II of Carinthia in 1123 or 1124. Later in the 12th century, Archbishop Conrad I significantly enlarged the complex, which included building the Rupert Chapel by approximately 1140. From that time onward, the castle functioned as a secondary residence for Salzburg’s archbishops and provided a safe haven during times of military conflict.

Several notable figures are connected with the castle’s history. King Conrad III lodged here in 1149 after returning from the Second Crusade, while Emperor Frederick I Barbarossa took possession in 1170, partly because the archbishop was allied with Pope Alexander III. The castle also witnessed the transit of King Richard I of England, who passed through Friesach during his return flight to England. In 1292, the fortress endured a siege by forces loyal to Duke Albert I during a rivalry involving Archbishop Rudolf.

The late 15th century brought further military activity when Hungarian troops occupied the castle for several years amid hostilities between Emperor Frederick III and King Matthias Corvinus of Hungary. Around 1495, Archbishop Leonhard von Keutschach undertook extensive renovations, modernizing both the castle and Friesach’s town fortifications, shaping their present-day appearance. However, over time, the fortress lost its military role and eventually was devastated by a fire in 1673. After that disaster, the castle was left abandoned and gradually fell into ruin.

Remains

The ruin of Burgruine Petersberg is built on Petersberg hill and is structured around two primary sections: the upper and lower courtyards, enclosed by fortified walls adapted over several centuries. The complex exhibits medieval construction techniques and Renaissance-era modifications.

Dominating the site is a six-story bergfried, or main tower, erected around the year 1200. This tall defensive tower has been partially restored since the late 1800s after a period of decay. Within it stands the Rupert Chapel, a notable religious chamber historically used for worship and now serving as Friesach’s city museum. Adjacent to this large tower are the remains of an older chapel, known either as the Gebhard or Conrad Chapel, reflecting earlier phases of ecclesiastical architecture within the castle grounds.

The lower courtyard, called the Unterer Burghof, originally contained multiple buildings encircled by protective walls. Of these, the southern building is the best-preserved; it formerly housed the castle captain and dates to the 16th century. This structure is recognizable by its three stories and an arcade façade, an architectural feature consisting of a series of arches supported by columns. Today, this building accommodates a restaurant, indicating its adaptive reuse.

On the western and northern sides of the lower courtyard lie ruins belonging to former representative residences, constructed between the 13th and 15th centuries. Among these are the remains of the Eberhard II Palace and the Leonhardsbau, buildings that once served important administrative and ceremonial functions within the fortress.

The upper courtyard, or Oberhof, sits on the rocky summit of Petersberg hill and forms a large fortified enclosure. It is fortified with half-towers—projecting defensive towers that cover the adjacent curtain walls—on both its northern and southern edges. Access to this elevated area was gained primarily through the main western gate, remnants of which, including parts of the original gate tower, survive to this day. Additionally, there was a northern entrance connecting to the upper courtyard.

Significant architectural elements from the Renaissance period are visible in the lower courtyard’s southern building, in particular the arcaded façade. Overall, these surviving features provide a layered record of the castle’s evolution from its medieval origins through periods of reconstruction and modern adaptation before its eventual decline.