IsleOfBute.co.ukIsle of Bute History
It is likely that before the Gaels arrived and absorbed Bute into the Cenél Comgall of Dál Riata that the island was home to a people who spoke a Brythonic language (akin to modern day Welsh). Later during the Viking period the island was known as Rothesay and the main town on the island was Bute. Widespread and long term mis-use of the titles was eventually officially recognised and the names were swapped to reflect popular usage.
After the Viking period the island was not granted to the Lord of the Isles as were most of the islands off Scotland's west coast. Instead Bute became the personal property of the Scottish monarchy.
In the 1940s and 1950s Bute served as a large naval headquarters.