The Earldom of Ross stretched from Skye to Inverness-shire, a vast inheritance that should have descended through the female line by a charter King David II had granted in 1370. When the last Earl's son Alexander Leslie died, leaving only a sickly daughter Euphemia, the line of succession ran clearly enough on paper. Donald of Islay had married Mariota, the dead earl's sister. By the old rules, the title should have passed to her. Albany, regent for his ineffective brother Robert III and after 1406 effectively ruler of Scotland, saw it differently. He maneuvered Euphemia into a nunnery and arranged for the earldom to pass to his own younger son, John. Donald assembled his forces at Ardtornish Castle on the Sound of Mull. The Lord of the Isles did not intend to lose Ross to a paper claim and a regent's ambition.

Donald moved fast. He met the Mackays of Strathnaver at Dingwall, seat of the Earls of Ross, and beat them there in a sharp fight. He captured Dingwall Castle, garrisoned it, and pushed east, his men committing what the chroniclers called great excesses along the way. By July he had crossed the Mounth and reached Bennachie, the last hill of the Grampians before the coastal plain opens toward the sea. From its slopes Aberdeen lay visible to the southeast - a wealthy burgh full of merchants and granaries. Word reached Mar at Kildrummy. The Earl of Mar was the bastard son of the Wolf of Badenoch, a hard man raised in hard country, and he rode for the Garioch with every knight and burgess he could rally. Sir Robert Davidson, Provost of Aberdeen, came up with the city's burgesses to fight beside him.

The armies met on 24 July 1411 on the open ground at Harlaw, two miles northwest of Inverurie. Mar's host was small - perhaps one or two thousand against Donald's reported ten - but it was heavily armoured. Sir Gilbert de Greenlaw, whose tombstone survives in Kinkell Church, fought in plate armour over a mail-reinforced arming doublet, bascinet on his head, a hand-and-a-half sword at his hip. The Islesmen came on with axe and claymore against this iron column and broke themselves on it. Wave after wave fell to the spears of Scrymgeour's foot. But the knights died too. Provost Davidson was killed beside most of the Aberdeen burgesses he had led north. The Chattan Federation lost so many of Clan MacBean that Mackintosh, their chief, mourned them by name in his chronicle. Night came down with both armies bloodied beyond endurance, both expecting to fight again at dawn. Instead, Donald withdrew west in the dark. Mar, too weak to pursue, held the field. By the rules of medieval combat, that made it a victory - but it was a victory nobody had wanted to win at this price.

Tradition says Mar founded the Chapel of Garioch after the battle, to have masses sung for the souls of the fallen. Several cairns once marked the ground - Drum's Cairn, Provost Davidson's Cairn, Donald's Tomb, the Liggars Stane - though little remains of them now. In 1837, twelve human skeletons were dug from the earth northeast of Harlaw House. No weapons or armour from the battle have ever been recovered: the iron was too valuable to leave behind. Historic Scotland inventoried and protected the battlefield in 2011, six hundred years to the year after the killing. Sir Walter Scott wove Harlaw into his 1816 novel The Antiquary through Elspeth's ballad, and Bonnie Rideout's album Harlaw, Scotland 1411 carries its tune forward still. Whether you see it as Highlander against Lowlander, Gael against Scot, or simply two clans of cousins fighting over an inheritance, the field is quiet now, holding its dead under the Aberdeenshire wind.