Natural wooden castle there in Olesnica certainly already in the early thirteenth century. The first element of the stone was erected within its fortifications in the late thirteenth and fourteenth century cylindrical tower with a diameter of 11 meters. At the beginning of the fourteenth century was created Duchy of Oels, therefore, the seat of the princes had to be developed. He did this before the middle of the fourteenth century, Konrad I, Duke of raising a large castle on a plan similar to the square of almost 50 meters, which had the main wing houses along the north-west curtain walls and a smaller wing at the south-west curtain. The southern corner was a rectangular tower, a cylindrical tower located in the eastern corner of defending the entry placed in the north-east curtain. The castle was located within the city's fortifications,
Reconstruction of the medieval castle of John Salma, 'Lexicon of castles in Poland' [source]
but was also surrounded by the side of the city moat. Construction work on the first assumption was still made before the end of the fourteenth century.
After 1492, after the death of the last of the princes Oleśnica castle was in the hands of the Czech Republic. In 1542, Prince John of Podebrad began rebuilding in Renaissance style mansion on the transformation of north-west wing. After a design by Francesco Parra was built east of the castle walls a new wing, called the house of widows, and a cylindrical tower and ośmiobocznie superstructured zwieńczono Renaissance cupola. Another Duke Charles II of Podebrad expanded residence in the years 1585-1610, and was recruited to the work of architect Bernard Niuron. Cylindrical tower with two new wings - first south-east, then north-east of the gate, which was connected with the house of widows. The whole earth was surrounded by a modern bastion fortifications.
In the years 1613-1616 were built indoor porch, connecting the castle with the parish church, where there was a lodge of the Prince. Small works suitable for decorating the baroque castle of the elements was carried out during the seventeenth and eighteenth century and nineteenth century, was rebuilt wing of the north-east. In the years 1896-1901 the castle was restored, while carrying out the work of J. Maas decided to restore the appearance of the Renaissance.
During World War II deprived of care had declined a little castle, but the reconstruction has restored the years 1970-1976
Frederick Bernard Wernher, Topography of Silesia 1744-1768
its former glory. Found in the castle is a museum and other cultural institutions.