One of the 'official'Campbell of Airds 2000: pp. 220–222. Clan Campbell septs is MacPhedran—a name derived from MacPheaderain, meaning "son of little Peader". The Gaelic Peadar is a cognate of the English Peter; and both are forms of the Greek Petros, meaning "stone", "rock".Hanks; Hodges 2006: pp. 219, 354. William Buchanan of Auchmar's 18th-century account of the surname MacAulay states that the original member of this sept was a MacAulay.Buchanan of Auchmar 1820: pp. 119–120. This sept dwelt in the lands of Sonachan, on Loch Awe, in what is largely Clan Campbell territory. The earliest account of the sept is in 1439, when Domenicus M'Federan was granted confirmation for the lands of Sonachan by Sir Duncan Campbell of Lochawe.Campbell of Airds 2000: pp. 254–255. According to David Sellar, the MacArthurs of Darleith descend from the MacAulays of Ardincaple. Darleith is located quite close to the old MacAulay seat at Ardincaple, about .
