Coeffin Castle was built on the site of a Viking fortress. The name Coeffin is thought to come from Caifen who was a Viking prince, and whose sister supposedly haunted the castle until her remains were taken back to be buried beside her lover in Norway.
Coeffin Castle was built in the 13th century, probably by the MacDougalls of Lorn. Lismore was an important site within their lordship, being the location of St. Moluag's Cathedral, seat of the Bishop of Argyll. The first written evidence of the castle occurs in 1469–70, when it was granted to Sir Colin Campbell of Glenorchy by Colin Campbell, 1st Earl of Argyll. It is unlikely to have been occupied in post-mediaeval times.
The ruins comprise an oblong hall-house and an irregularly shaped bailey. The great hall is an irregular rectangle, measuring 20.3 by 10.4 metres. The walls are from 2.1 to 2.4 metres thick. The bailey was mostly built at a later date than the hall. An external stair probably linked the entrance, in the north-east wall, to the bailey. A second door gave access to the sea to the south-west.
References:The Château du Haut-Koenigsbourg is situated in a strategic area on a rocky spur overlooking the Upper Rhine Plain, it was used by successive powers from the Middle Ages until the Thirty Years' War when it was abandoned. From 1900 to 1908 it was rebuilt at the behest of the German kaiser Wilhelm II. Today it is a major tourist site, attracting more than 500,000 visitors a year.
The first records of a castle built by the Hohenstaufens date back to 1147. The fortress changed its name to Koenigsburg (royal castle) around 1157. The castle was handed over to the Tiersteins by the Habsburgs following its destruction in 1462. They rebuilt and enlarged it, installing a defensive system designed to withstand artillery fire.
The fortification work accomplished over the 15th century did not suffice to keep the Swedish artillery at bay during the Thirty Years War, and the defences were overrun.