In 1462, John MacDonald of Islay, Earl of Ross and Lord of the Isles, signed a secret treaty with Edward IV of England — the Treaty of Westminster-Ardtornish. The terms were simple: become Edward's vassal, and England would help him conquer the north of Scotland. When James III of Scotland uncovered the deal in 1476, he stripped MacDonald of his mainland possessions. MacDonald spent the next few years trying to take them back. He sent most of his fleet south with his kinsman Donald Balloch to ravage the West Coast. Then he took 500 to 600 men around the top of Scotland to the Dornoch Firth, landed within sight of Dunrobin Castle, and began the brief, bloody campaign that would end on the sands of Strathfleet.
It is hard to overstate how strange this expedition was. John MacDonald commanded one of the most powerful military forces in the British Isles - the galley fleets of the Hebrides, the manpower of Islay and the Western Highlands, alliances stretching from Ulster to Lewis. By 1476, all of it was crumbling. The English alliance was exposed, the Crown was hostile, and his own son Angus Og was already restive. The Dornoch Firth expedition reads like a desperate gamble: land far from his enemies' centres of power, seize a foothold in friendly Ross territory, perhaps draw the Bishop of Caithness or sympathetic clans to his cause. Instead he landed in the heart of Clan Sutherland country - the Sutherlands controlled much of the far north and had no intention of bowing to Hebridean overlordship.
MacDonald's men first camped before Skibo Castle on the south shore of the Dornoch Firth - a possession of the Bishop of Caithness, who was not present to defend it. John Sutherland, 7th Earl of Sutherland, sent a force under Neill Murray of Aberscross to watch the islanders and keep the country quiet. When MacDonald's troops began to ravage the surrounding lands - the standard Highland tactic for extracting submission and supplies - Murray attacked. He drove the invaders off the castle approaches. One of their captains, a man named Donald Dubh-na-Soirn, was killed in the action, along with about fifty of his men. It was not a decisive battle - more a sharp rebuke - but it told MacDonald that this country would not be his for the taking.
Stung by the defeat at Skibo, MacDonald sent a fresh force - some of his own men plus a company of Ross men he had recruited - up the coast toward Loch Fleet, just south of Dunrobin Castle. The plan was to flank around the Sutherland defences and threaten the Earl's seat directly. The Earl sent his own brother Robert with a hand-picked force to meet them. The two sides clashed "on the sands of Strathfleet," the flat tidal land where the River Fleet meets the sea. The Wardlaw Manuscript called it a "fierce and bloody struggle." The islanders broke. The survivors were pursued the length of the firth as far as Bonar Bridge, harried across the moors. "With great slaughter" is how the chronicles record it - the kind of euphemism that hides hundreds of deaths.
What happened next is the most surprising thing in the whole affair. The Sutherlands did not press their advantage. Instead, the Earl arranged a marriage to John MacDonald's sister Margaret, sealing an alliance with the very family he had just defeated. It was practical politics - both sides had reasons to want peace - but it was also the end of organised MacDonald ambition in the north. The defeat at Strathfleet may have been a factor in the internal collapse that followed: in 1480 or 1483, John MacDonald's son Angus Og rebelled against him, and the two fought the Battle of Bloody Bay off the coast of Mull. The Lordship of the Isles was finished as an independent power within a generation. It started to end, quietly, on a tidal flat in Sutherland.
The Skibo and Strathfleet battle sites span the inner Dornoch Firth around 57.95°N, 4.07°W. Skibo Castle sits on the south shore, about 3 miles west of Dornoch - the present castle was largely rebuilt in the 19th and 20th centuries by Andrew Carnegie, but the site occupies the original medieval position. Strathfleet lies 8 miles north, where the River Fleet enters Loch Fleet near Golspie. From cruise altitude north of Inverness (EGPE), 50 miles south, the Dornoch Firth is the broad inlet south of the Sutherland mountains; Loch Fleet is the smaller tidal loch further north, sealed behind The Mound causeway. Best viewed at 2,500-4,000 ft AGL in clear weather; the tidal mudflats catch the light dramatically at low tide.