The castle was built to protect the age-old route from the Silesian plains through Javorník and the Landeck pass to Kladsko (Glatz, Kłodzko; now Poland, but part of the Bohemian kingdom from 1327–1740). It was probably preceded by a hill-fort, protecting the Bohemian borders. The castle is mentioned in the written sources in 1307 as the property of the Bishops of Wrocław (Breslau); however part of the estate was also part of the appendage of the princes of Świdnica (Schweidnitz) in the 14th century. At the latest by 1420 the whole of Javorník belonged to the Bishops of Wrocław. The castle complex occupies a rather steep promontory and was probably originally divided into two parts: a raised core with a two-room palace and a lowered part. It was divided from the surrounding elevated plateau by a deep saddle of land, used as a mighty moat. An outer bailey was joined to the castle on the east side. In 1428 it was conquered by the Hussites and razed. The reconstruction of the castle area, which developed into a palace throughout several building phases, was initiated by Wrocław Bishop Jan Roth. It was completed by Prince-Bishop Johannes Thurzo in 1509 in Late Gothic style and the castle received the name Jánský Vrch – John‘s Hill (as John the Baptist was the patron of the Bishops of Wrocław). Some further building activity took place at the beginning of the 17th century (the northern corner of the castle was built, a four-axis arcaded loggia on bossed pillars appeared in the court), but mostly after the 18th century by Prince-Bishop Phillipp Gothard von Schaffgotsch. This noted promoter of music and freemason moved his seat here in 1757, at the outbreak of the Seven Year War, and had the whole complex reconstructed as a Baroque residence for the Austrian part of the Nysa (Neisse) principality: construction of the southern courtyard, expansion of the castle in the direction of the moat by a double height building, decoration of the interior and other works, and established a terrace garden in the surroundings.The finishing touches were also put to the paintings and sculptural decoration of the upper chapel, which also contained Late Gothic artefacts. The castle became a famous cultural centre in Bishop Schaffgotsch’s era and well-known personalities from the artistic and literary spheres stayed here. The Viennese violinist Carl Ditters worked as a composer and conductor for the choir, and was raised to the ranks of the nobility (von Dittersdorf) for his services. The castle received its current appearance at the beginning of the 19th century under Bishop Joseph Christian Hohenlohe-Waldenburg-Bartenstein (construction of the state staircase building on the west side, an out-building in the entrance courtyard and other). There are now high quality Neo-Classical interiors. A small French ornamental park was founded under the castle by Bishop Schaffgotsch in 1776. The first section of the landscape park developed on the southern slope of the castle hill under Bishop Johann Christian Hohenlohe-Waldenburg in 1800. From 1837–40 it was expanded under Bishop Leopold Sedlnický, and it extended to the western and northern hillside under Bishop Melchior Diepenbrock in the 1840s. The castle served as the summer seat of the bishops until the 20th century, hence the original furniture has been preserved here (including for example the wallpapers), dating mostly from the second and third quarters of the 19th century. There is also one of the largest collections of pipes in the Czech lands and a collection of curtains and net curtains. The gas lighting from the beginning of the 20th century has also been preserved.