The first fortification at this site was likely built in the second half of the 10th century by the counts of Winterthur. It is first mentioned in 1027 under the name of Chuigeburg, which name points to an original use as a refuge castle for livestock. The modern spelling Kyburg first occurs in the 1230s The early castle was destroyed in 1028 or 1030 by emperor Conrad II. It was rebuilt and soon became the center of the county of Kyburg which was formed in 1053 as a possession of the counts of Dillingen. In 1079, during the Investiture Controversy, the castle was attacked and partially destroyed by Abbot Ulrich II of St. Gall. By 1096 the counts of Dillingen included count of Kyburg as one of their titles. By 1180, the counts of Kyburg emerged as a cadet line of the Dillingen family. They rose to be the most important noble family in the Swiss plateau beside the Habsburg and the House of Savoy by the 13th century. After the death of the last count in 1264 Rudolph of Habsburg claimed the inheritance for his family. With one interruption the Imperial Regalia of the Holy Roman Empire were kept in the castle between 1273 and 1322. The core of the extant castle originates in the 13th century, with the addition of substantial parts in the course of the 13th and 14th centuries. It is among the largest surviving medieval castle complexes in Switzerland, consisting of a bergfried and palas with additional residential and economic buildings and a chapel, all connected by a ring wall enclosing a large courtyard. In the 1424 the city ofZürich bought the county, and the castle became the seat of the reeve. The dilapidated castle was substantially renovated at this time. The chapel has substantial late Gothic frescoes commissioned by Zürich. Substantial changes to the structure were made under reeve Hans Rudolf Lavater during 1527/8. Further changes were made to the structure in the early modern period. The castle was plundered by the local populace in 1798, but it was again used as administrative seat from 1803 until 1831, when it was sold by auction to one Franz Heinrich Hirzel of Winterthur who intended to use it as a quarry. To prevent its destruction, the castle was bought by the exiled Polish count Alexander Sobansky in 1835. Sobansky resided in the castle for the next 30 years. In 1865 the castle was opened as a "Castle and Art Museum" by Matthäus Pfau. Under the next owner, Eduard Bodmer, the museum remained open. In 1917 the Canton of Zurich bought the castle back, since 1999 a society runs it, the Verein Museum Schloss Kyburg.
Events
Every summer the Kyburgiade, an international chamber music festival, takes place in the inner courtyard of the castle.
Castle site
The castle forms an irregular quadrangle with a single courtyard atop a steep hill above the Töss valley. South of the castle, between the medieval neck ditches, is the French formal garden which was designed in 1700 by Caspar Schwarzenbach. The entrance to the castle is through the outer gate located on the north-east corner. The gate house was rebuilt in 1579-80 and decorated with coats of arms by Christoph and Josias Murer. A zwinger or narrow, defensive passage leads from the outer gate to the inner gate. A walkway goes over the zwinger and connects the palas or great hall with the Willenturm on the north corner of the castle. The inner gate is protected by the bergfried which was built in 1424 with a roof from 1444.
