Brauweiler Abbey, a former Benedictine monastery, founded and endowed in 1024 by Pfalzgraf Ezzo, count palatine of Lotharingia of the Ezzonian dynasty and his wife Matilda of Germany, a daughter of Emperor Otto II and Theophano. Ezzo and Matilda were buried here, as were their two eldest sons Liudolf, Count Palatine of Lotharingia (d. 1031) and Otto II, Duke of Swabia (d. 1047).
From 1065 until his death in 1091, Wolfhelm of Brauweiler, later Saint Wolfhelm, was abbot here. His relics were enshrined in the abbey church, and miracles were reported at his tomb, but all traces of them were lost centuries ago.
The present abbey church, now the parish church of Saint Nicholas and Saint Medardus, is the third building on the site, built between 1136 and 1220 or later. The abbey was dissolved in the secularisation of 1803. The premises were subsequently used, under a Napoleonic law, as a hostel for beggars, and from 1815 under the Prussian regime as a workhouse.
From 1933 to 1945 the buildings were used for the internment, torture, and murder of political and social 'undesirables' by the Gestapo and the civil authorities of the Nazi government. Prisoners included Konrad Adenauer, the former mayor of Cologne and first Chancellor of the Federal Republic of Germany. From 1945 to 1949, it was an open camp for displaced persons administered first by the British Army and then by United Nations Relief and Rehabilitation Administration.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.