Fergus, Earl of Buchan

Buchan is also the name of a much larger historic province and earldom, shown on maps as early as 1708, which included the whole of the modern committee area called Buchan.

In Pictish times, Buchan was located within the kingdom of Ce. There is considerable ancient history in this geographic area, especially slightly northwest of Cruden Bay, where the Catto Long Barrow and numerous tumuli are found.

The Earldom of Mar and Buchan formed one of the seven original Scottish earldoms; later the Earl of Buchan became separated from Mar.

Source: https://en.wikipedia.org/wiki/Buchan