Dillenburg’s history goes back over 600 years. It was the ancestral seat of the Orange branch of the House of Nassau. The town’s most prominent landmark, the Wilhelmsturm (William’s Tower) on Schlossberg (Castle Hill), was built in the 1870s as a tribute to William I of Orange, born in Dillenburg Castle in 1533 as Prince of Nassau-Dillenburg. He was the great-grandfather of William III, Prince of Orange and King of England who, with his wife Mary, ushered in an epoch of immense achievement in England. Today the tower houses the museum dedicated to the Orange-Nassau family. Of the castle, which was built in the 12th century and destroyed in the Seven Years’ War, there remains today only the old Stockhaus (a former prison); the rest is in ruins.
The impressive underground defence system, the Kasematten underneath the tower, dates from the 16th century and is unique in Germany. In times of war it was able to accommodate more than 2,000 soldiers. Today parts of the casemates and their defence corridors are open to the public and provide a good impression of the extent of this fortification.
The Johanniskirche (Church of St John) at the foot of Castle Hill, built in the 15th century, is the resting place of members of the House of Nassau-Dillenburg from which the Dutch royal family originated.
Dillenburg has a long tradition of horse-breeding. The Royal Stables date back to the 18th century, together with the impressive riding hall of 1789/90, since 1869 they form part of the Hessisches Landgestüt Dillenburg which is today at the heart of an important equestrian centre, with a Stagecoach Museum in the old Orangery. Every two years the Hengstparade takes place, a parade of stallions and horse tournaments which draws crowds of visitors from all over Germany and beyond.