Configuration. The stone castle was built as a roughly rectangular curtain wall 2 metres thick and 8 metres tall. It was augmented by two towers on the North and West sides.
Notes: The route to the castle, a long single track road, is sign-posted. It is situated within a holiday resort with no vehicular access for castle visitors - park at the sign-posted lay-by.
One of the earliest stone castles in Scotland, Castle Sween was built by the Nordic ruler of Knapdale to provide a secure base for his ships. It continued with his descendants, Clan MacSween, until the thirteen century after which it passed first to the MacDonalds, Lords of the Isles and later the Campbells.
HISTORY OF CASTLE SWEEN
Castle Sween was probably built by Suibhne (later anglised to Sween), Lord of Knapdale in the late twelfth century. At this time Argyll was not part of Scotland but was under Norse control with the sea lochs of the Western coast providing ideal harbours for their warships. This was certainly the case at Castle Sween where the sandy shores were ideal for beaching the small galleys of the era. The castle itself was configured into a strongly built rectangular curtain wall over 2 metres thick and 8 metres tall. This was probably augmented by additional earth and timber defences that enclosed a secure landing point for Suibhne's ships. His descendants became the MacSweens holding their lands - which stretched from Loch Awe in the north to Loch Fyne in the South - until the late thirteenth century.
Argyll formally became part of Scotland following the treaty of Perth (1266) when King Magnus IV of Norway ceded the domain. However, around this time, the MacSween's lost control of the castle to the Stewarts, Earls of Menteith. John MacSween made an unsuccessful attempt to re-take the castle in 1300. They also tried to enlist the support of the English - in 1310 Edward II formally granted Knapdale to them - but English fortunes were on the wane and with their decisive defeat at the Battle of Bannockburn (1314) the MacSween claim foundered.
Following the Wars of Independence Castle Sween was granted by Robert I to Angus Óg of Islay and then onto his son John MacDonald, Lord of the Isles. The castle remained a MacDonald estate for over a hundred years although it was never their primary residence. Instead the site was entrusted to their kinsmen, first members of the MacNeils and then the MacMillans. By the late fifteenth century though the MacDonalds had come into conflict with King James III. In 1481, with the MacDonald power broken, James III granted the castle to Colin Campbell, Earl of Argyll.
In 1644, during the War of Three Kingdoms, Castle Sween was attacked by Alasdair Mac Colla who was a descendant of the MacDonalds. The damage was seemingly significant and the structure was not repaired.