The Château de Rothenbourg is a ruined castle in the commune of Philippsbourg. The castle, built on a hill called Rothenberg or Rodenberg, dates back to the 9th century. Around 912, the Bishop of Strasbourg, Otbert, pursued by rebellious subjects, took refuge at Rathburg which is perhaps Rothenburg, and was assassinated there shortly after.
The castle was certainly built by the Duke of Lorraine in the 13th century, and is constructed of dressed sandstone. At the end of the 13th century, it passed to the Counts of Zweibrücken-Bitsch. In the 14th century, Rothenburg partly belonged to Count Walram of Zweibrücken-Bitsch who gave it as a fiefdom in 1353 to Gerhard Harnasch von Weisskirchen.
In 1368, Rothenburg was taken and destroyed by the Strasbourgeois.
The castle seems to have given its name to the Blick de Rothenburg family, who held several fiefs from the Lords of Bitche, and who died out in 1749.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.