The Castello Normanno ('Norman Castle') in Paternò was built in 1072 by Count Roger I of Sicily to protect the Simeto valley from Islamic raids. The first nucleus of the fortress was soon enlarged, and it subsequently lost its original military functions. Under Henry VI it was made the seat of the Count of Paternò, assigned to his fellow Swabian Bartholomew of Luci. Later the castle housed kings and queens, such as Henry's son Emperor Frederick II, Eleanor of Anjou and Blanche I of Navarre, as the castle had been included in the so-called Camera Reginale estates ('Queen's Chamber') by King Frederick III of Sicily.
The Chamber was abolished in the 15th century, and in 1431 the castle was acquired by the Special family; until 1456 it was owned by the Moncada family. Used as a jail, in the following centuries it became increasingly decayed, until restoration work begun in the 19th century brought it back to its ancient prominence.
The castle has a rectangular plan, on three floors, with a height of 34 m. Originally, it had Ghibelline-style merlons, of which today only remains can be seen. Notable is the colour effect created by the dark shade of the stones and the frames of the Gothic-style mullioned windows, in white limestone.
The first-storey houses several service chambers and the Chapel of St. John, decorated with precious 13th-century frescoes. The piano nobile houses a large Weapons Hall. The king's residence was located in the upper floor.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.