Caldicot Castle is an extensive stone medieval castle, built near the site of Harold Godwinson's former Saxon castle by the Norman earls of Hereford from about 1100. Humphrey III de Bohun was the probable builder, in about 1170, of the stone keep and curtain walls of the present-day castle. The Bohun family held the manor and castle of Caldicot for more than two centuries, over eight generations.
In 1381, Essex was convulsed by the Peasants' Revolt. This may be why Thomas decided to spend part of that year in Caldicot. During his stay he gave orders for major new work to be done on the castle. A new gatehouse and drawbridge were constructed. At the rear of the castle a dovecote was replaced by a new tower with private chambers, now known as the Woodstock tower. At the foot of the Woodstock tower two carved stones were to be placed, one marked 'Thomas' the other 'Alianore'.
In the 16th-17th centuries Caldicot Castle was evidently neglected, fell into ruin and became little more than a farmyard. In 1964, Chepstow Rural District Council bought the castle. The building, including a small museum, was opened to the public in 1965.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.