In line 16 (p.338) of the Saga of Haakon Haakonsson, the word ‘kastala’ appears. This refers to Rothesay Castle on the Isle of Bute, which Haakon, king of Norway from 1217 to 1263, attacked about 1230s.
The sentence is translated thus:
‘They should go to the Bot to meet the men who were sent there. And when they arrived, they were told that these men had gone to a castle* and won it in the way that those who sat there, had given the castle and made their lives from the Norwegians’.
This is the earliest recorded account of an assault on a Scottish castle. Haakon returned in 1263, re-taking the Castle, and the Hebrides, a Norwegian possession which was finally ceded to Scotland in 1266.
One outcome from the Battle of Largs (2 October 1263), an engagement of the Scottish-Norwegian War, was that it ended Norse influence in western Scotland.
‘Hakonar Saga’, in Icelandic Sagas, Vol. II. Edited by Gudbrand Vigfusson. London: Eyre and Spottiswoode, 1887.