The Ducal Rotunda of the Virgin Mary and St Catherine is Znojmo's most valuable monument, and features one of the oldest fresco in the Czech lands. Particular importance of this painting is that besides the religious motives it displays also the praising portrayal of the ruling Přemyslid dynasty.
The painting was commissioned by Konrad II of Znojmo on the occasion of his wedding with Mary, daughter of Uroš of Serbia in 1134. Apart of the donor couple, Konrad and Mary, the identity of the other depicted members of the dynasty is disputed among the historians. With two exceptions being the Přemysl the Ploughman, the legendary ancestor of the dynasty, and Vratislaus I, the first King of Bohemia.References:
First record of Kastelholma (or Kastelholm) castle is from the year 1388 in the contract of Queen Margaret I of Denmark, where a large portion of the inheritance of Bo Jonsson Grip was given to the queen. The heyday of the castle was in the 15th and 16th centuries when it was administrated by Danish and Swedish kings and stewards of the realms. Kastelhoma was expanded and enhanced several times.
In the end of 16th century castle was owned by the previous queen Catherine Jagellon (Stenbock), an enemy of the King of Sweden Eric XIV. King Eric conquered Kastelholma in 1599 and all defending officers were taken to Turku and executed. The castle was damaged under the siege and it took 30 years to renovate it.
In 1634 Åland was joined with the County of Åbo and Björneborg and Kastelholma lost its administrative status.