In traditional genealogies of the Clan Campbell, its origins are placed amongst the ancient Britons of Strathclyde. However, the earliest Campbell in written records is Gillespie who is recorded in 1263. Early grants to Gillespie and his relations were almost all in east-central Scotland. However, the family's connection with Argyll came some generations before when a Campbell married the heiress of the O'Duines and she brought with her the Lordship of Loch Awe. Because of this the early clan name was Clan O'Duine and this was later supplanted by the style Clan Diarmid. This name came from a fancied connection to Diarmid the Boar, a great hero from early Celtic mythology.
The original seat of the Clan Campbell was either Innis Chonnell Castle on Loch Awe or Caisteal na Nigheann Ruaidh on Loch Avich. The clan's power soon spread throughout Argyll, however at first the Campbells were under the domination of the Lords of Lorne, chiefs of Clan MacDougall. The MacDougalls killed the Campbell chief Cailean Mór (Colin Campbell) in 1296 - see Battle of Red Ford). All of the subsequent chiefs of Clan Campbell have taken MacCailean Mór as their Gaelic patronymic.
Between 1200 and 1500 the Campbells emerged as one of the most powerful families in Scotland, dominant in Argyll and capable of wielding a wider influence and authority from Edinburgh to the Hebrides and western Highlands.
