Sønderborg Castle

Sønderborg Castle, known locally as Sønderborg Slot, stands majestically in the southern Danish town of Sønderborg. This historic gem, one of the oldest non-religious buildings in Sønderjylland, has a storied past that spans centuries and is deeply intertwined with the region's history. Today, Sønderborg Castle houses a museum, offering visitors a fascinating glimpse into Denmark's rich cultural heritage.

The Architecture of Sønderborg Castle

Sønderborg Castle is an impressive quadrangular structure, nearly rhombus-shaped, encircling a spacious courtyard. Built primarily from red brick, the three-story castle rests on a sturdy foundation of massive stone blocks. Originally, the castle was fortified with imposing towers at each corner, crowned with Renaissance-style caps. Today, only the foundations of these towers remain, with a blunt turret still visible at the northwestern corner.

The castle's north wall retains traces of the medieval entrance, now bricked up, while the current main access is on the east side, leading into the expansive courtyard adorned with three slender stair towers. Some of the castle's interior rooms have preserved their original layout, notably the grand 34-meter-long Knights' Hall and the Renaissance chapel built between 1568 and 1570 under the commission of Dorothea of Saxe-Lauenburg-Ratzeburg. Visitors can also explore parts of the former dungeon facilities, adding a thrilling touch to the tour.

During the Renaissance, the castle's gables and dormers were richly decorated with period elements, which were removed during 18th-century renovations. Since then, the castle's façades have maintained a severe appearance, enlivened only by the numerous windows. The outer fortifications that once surrounded the castle, transforming it into a formidable fortress, have mostly been dismantled, with remnants still visible on the east side.

The Origins and Early History

The origins of Sønderborg Castle date back to the 12th century, when Danish King Valdemar I ordered the construction of a fortress to defend against Wendish pirate attacks. Initially, the fortress consisted mainly of a single heavy tower, whose remnants are now concealed within the castle's northeastern walls. Positioned strategically on the Flensburg Fjord, the fortress was named Sønderborg, meaning Southern Castle, with a counterpart to the north called Nordborg.

The first recorded mention of the castle is from 1253, when King Christopher I of Denmark captured and partially demolished it. Nevertheless, the castle was rebuilt, and by the mid-13th century, it featured a more substantial tower and defensive walls forming the present-day castle's layout. During this period, the castle also served as a prison, notably holding Peder Höfel, accused of murdering King Eric Klipping, for an extended period.

Throughout the 14th century, the castle underwent significant expansions, including the addition of a new tower at the southeastern corner around 1375. These expansions coincided with various conflicts involving the castle, which saw it change hands multiple times. By the 15th century, the settlement around the castle had grown into the town of Sønderborg.

Conflicts and Transformations

From the 14th to the 15th centuries, Sønderborg Castle was at the center of numerous conflicts. In 1325, King Christopher II captured the castle during a war with the Counts of Holstein, only to lose it and his crown shortly afterward. In 1353, the castle became the residence of Duke Valdemar V, who had previously been King of Denmark as Valdemar III. The peaceful relationship between the king and the duke eventually soured, leading to a siege of the castle by King Valdemar Atterdag in 1358. The castle was spared thanks to the intervention of the duke's wife, Duchess Regitze.

In the early 15th century, the castle was besieged by King Eric of Pomerania during his conflicts with the Hanseatic League and the Counts of Holstein. Despite these turbulent times, the castle remained a significant stronghold, with further fortifications added around 1500, including the construction of the northwest tower and a forecourt with bastions.

The Reformation and Renaissance Transformations

The Reformation brought significant changes to Sønderborg Castle. In 1532, the deposed King Christian II was imprisoned in the castle for 17 years. Contrary to popular legend, his imprisonment was relatively comfortable, allowing him to maintain a semblance of court life. During his captivity, he commissioned the first Danish translation of the New Testament, a rare copy of which is still housed in the castle.

Under King Christian III and his son Duke John of Schleswig-Holstein-Sonderburg, the castle was transformed into a splendid Renaissance residence. However, the duchy of Schleswig-Holstein-Sonderburg faced financial difficulties, leading to the castle and town reverting to the Danish crown in 1667.

Modern-Day Sønderborg Castle

Today, Sønderborg Castle stands as a testament to Denmark's rich history, offering visitors a chance to explore its grand halls, chapel, and dungeons. The castle's museum showcases a wide array of exhibits, from medieval artifacts to displays on the region's cultural heritage. A visit to Sønderborg Castle is a journey through time, providing a captivating glimpse into the past and the enduring legacy of this remarkable fortress.