The influence of military, political and economic conditions on the townscape and town walls

Because of its border position, Radkersburg was strategically important as a fortress from the beginning. This fortress had the task of breaking up an initial attack and therefore preventing penetration of enemies through the lower Mur valley towards the state capital. In the year 1582, Radkersburg was promoted to an imperial fortress at the Reichstag in Augsburg.
In the Middle Ages, Radkersburg was surrounded by a simple ring wall and enclosed by a moat. Two gates (later known as Ungartor and Grazertor) were connected with each other by a road following a north-south direction – today’s Langgasse.
According to the latest scientific knowledge, the old settlement was enlarged under Albrecht I of Habsburg. This building was carried out following a precise plan and the town of Bad Radkersburg as it is today grew up out of this. Walls and towers surrounded the building, and the town planners took in the castle in the area of the Pfarrgasse, or the upper Langgasse, integrating it in the new construction. The north-east corner, which is today’s Tabor area, was only later built up as a fortified corner.
The defence towers were an essential part of the fortress in the Middle Ages and four of these are more or less well preserved in Radkersburg today: they are situated on the former Augustinian Monastery, the parish church, the Kapuziner Bastion and on the now so-called Obal tower. The task of building and maintaining the town’s fortifications, as well as its defence, was not only the duty of the town’s bourgeoisie and other citizens, but also of the people in the surrounding countryside.
On the other hand, the farmers were able to seek protection within the fortified town in times of danger.
The conflicts with the Ottoman Empire in the 16th century made restoration and modernisation of the fortress building indispensable. This was primarily in order to make the Styrian border secure, because Hungary was to a large extent under Ottoman control following the battle of Mohács in 1526. The defence had to be adjusted to new battle conditions – as was made clear during the battle for Vienna in 1529 – because the medieval fortress buildings could not oppose resistance against the improved firearms and artillery.
At first medieval fortresses were only repaired for financial and political reasons. The plans based on an overall fortification concept were only introduced after 1544. The centre of defence was the state capital of Graz, which had an inner and outer defence belt located in front of the town. Radkersburg was part of the inner line.
Italian master builders were called on because of their expert knowledge of building fortresses. Domenico dell’Allio from Lugano was put in charge of the site, so he was responsible for the fortifications of important borderlands like Varaždin, Graz, Ptuj, Maribor, Fuerstenfeld and Rann. The first extension phase in Radkersburg was therefore particularly marked by dell’Allio’s achievements. The modern defences in Radkersburg enclosed the existing medieval heart of the town including the ring wall. The main characteristics of the Renaissance fortress were bastions, curtain walls (a masonry wall connecting the bastions) and a deep moat. The first stage of building ended due to dell’Allio’s death in 1564.
The second stage began in 1570 under dell’Allio’s successor, Francesco Theobaldi. Completion of the fortress continued until the year 1591 and the construction costs were enormous (100,000 Gulden). Apart from problems with financing, catastrophes like fire and flooding, which destroyed work which had already been completed, had negative effects. For instance, in 1549 the city wall was badly damaged by fire which raged from the Mur gate to the tower of the Augustinian monastery. Reconstruction work was inevitable and was still being undertaken in 1574. Notwithstanding this, the fortress was given an insufficient certificate in the following year at the viewing by the royal master builder. He demanded a solution for security, to connect the spatially separate defence centres – the Schlossberg, the Gries district and the city. Should the enemy take the hill, this would provide an excellent position for shelling Radkersburg. However, the structure of the terrain of the hill prevented any practical feasibility of fulfilment of this demand.
Building was officially stopped in 1591, but the fortress of Radkersburg was never really completed. Time and again the fortifications were damaged by flood, fire and adverse weather conditions such as snow or rain, and had to be restored from time to time or rebuilt. The town was nearly laid open in 1605. Nevertheless, a very late and only hesitant decision was taken in Graz to carry out overall restoration works on the fortifications. The wall between the gun tower and the Clergymen’s Bastion was by then so badly damaged that a small child could step over it easily.
In the mid 17th century Martin Stier was therefore given the task of assessing the fortified borders because of their defence qualities, to record their condition at that time and to give advice for improvements. These works are about the earliest complete records of the town area of Radkersburg and the Schlossberg. Stier found that the town could not be defended without sufficient fortification of the Schlossberg. His recommendations regarded fortification of the Schlossberg as well as the Gries district, on the other side of the Mur: improvement of the bastions and construction of “covered ramparts” (in the area where the town park avenue is today) and re-creation of the west front of the town. Between the suburban bastion and the Mur Bastion there were no curtain walls and the moat was also missing. To remedy this defect, the Mur suburbs had to be removed, which took 3 months’ work of about 700 men.
Because of the scarce flow of funds and the extremely high cost of the work, realisation of the project with the measures recommended by Stier against endemic fires and flooding was not possible.
A few years after the report from Stier, an engineer, Michael Possaenner, also drew up a plan summarising his recommendations for improvement of the fortress at Radkersburg. On the whole, his suggestions were the same as Stier’s.
The outer limit of the town moat - today’s town park avenue - was integrated into the western part of the building as a “covered way”. The Upper Radkersburg Castle was probably also given a type of field fortification (consisting only of earthworks). More farsighted recommendations, such as fortification of the Schlossberg and the suburbs of Gries, which would have provided a better union of the separate defence centres, were never carried out. The reason for this mainly lies in the armed conflicts during the second half of the 17th century. The repair works were completed in 1644.
When the conflicts with the Ottoman Empire were drawing to a close in the 18th century, the significance of Radkersburg as a fortified town also ended. After the abandonment of the fortress (1773), the fortress lands were given to the town, and were then split up and sold to the inhabitants. The town was made accessible on more sides and both the town gates (Grazertor and Ungartor) were removed. Although there have been structural changes during the last 200 years, the central parts of the fortifications remain almost unchanged in their unique, enclosed form.