A Theorized Genesis 

Pinpointing our earliest Campbell ancestors  is  cumbersome;  like determining how in the Biblical Genesis, God actually created water and land.  Past and present scholars agree the Campbell name began in present day Scotland from either Gaelic, Briton, or Norman influence.   The Gaelic version asserts Campbell ancestors derived from the Kingdom of Dalriada originally in Northern Ireland which expanded into Western Scotland around  500 CE.   The ancient kingdom of Strathclyde, circa 450 CE to 1018 CE, a kingdom of early Britons stretched from present day Northern England to Scotland.  It's capital was Dumbarton.  The Strathclyde theory hypothesizes ancestors of the first Campbells actually originated within Strathclyde.  Finally, the third theory, and possibly least popular, hypothesizes Campbell Ancestors were Norman. The Normans were invaders from the Normandy area of present day France who were led by William the Conqueror.  

Great Colin, Cailean Mor and The Campbells of Lochawe

By 1292 CE, the Campbells were established on Lochawe in Argyll, Scotland and also presented a Barony.  They were then known as the Lords of Lochawe.  Cailean Mor, or Great Colin, is the son of Gillespic Cambel and is the ancestor from which the Chiefs of Clan Campbell take their blood title, MacCailean Mor, Son of Great Colin.  

Rise in Power and Titles 

Campbell prominence rose when Cailean Mor's son, Neil Campbell transferred his allegiance to Robert the Bruce who was crowned King of Scots in 1306 CE.  The allegiance would later see the Campbell Chiefdom granted additional  lands and wealth.  Neil Campbell wedded Mary Bruce, the sister of Robert The Bruce.  The Campbells were rewarded with "castles on forfeited estates." (McKerral 1953)

Over the next 700 years the Campbells power steadily rose with occasional decline throughout Argyll and Scotland.  This was based largely in the fact Chiefs of Clan Campbell fervently supported the Crown even after the union of the English and Scots Crowns in 1606.  Over the centuries, this support resulted in more titles and lands.  Overtime, the Lords became Earls, who became Marquesses, who eventually ascended to the title of Duke of Argyll.   The present Chief of Clan Campbell is the Master of the Royal Household in Scotland.  The current seat of the Family is Inveraray Castle where the Clan Campbell Chief is known as the Duke of Argyll.