Ben Macdui (Scottish Gaelic: Beinn Mac Duibh) is the second highest mountain in the United Kingdom after Ben Nevis, and the highest in the Cairngorms. After the defeat of Domnall mac Uilliam in 1187, Donnchad II, Earl of Fife, acquired Strathavon, territory stretching from Ballindalloch to Ben Macdui; because the mountain marked the western boundary of Donnchad's territory, historian and place-name scholar Professor G. W. S.