The siege of Blair Castle was a peculiarly Scottish affair, shaped by the fault lines that ran through individual families as much as through the nation. Blair Castle was the ancestral seat of James Murray, 2nd Duke of Atholl, who supported the British government of George II. But most of Clan Murray followed the Duke's younger brother, Lord George Murray, who had become the Jacobite army's most capable general. When the Duke of Cumberland arrived at Perth in February 1746 to take command of the government forces, he dispatched detachments to secure the Atholl country. Lieutenant Colonel Sir Andrew Agnew of the Royal Scots Fusiliers -- himself chief of Clan Agnew -- was sent with 300 men to garrison Blair Castle. A separate force of 200 under Lieutenant Colonel Webster occupied Castle Menzies nearby to guard the Tay bridge crossing.

On the morning of 17 March, Lord George Murray struck. Every outpost surrounding the castle was taken by surprise. Government soldiers stationed outside the walls were captured and made prisoners, reducing Agnew's garrison to roughly 270 men. The Jacobites, under Murray and Ewen MacPherson of Cluny, chief of Clan Macpherson, set up their headquarters in the village of Blair, a quarter mile to the southeast, and opened fire on the castle from close range. They sent a formal summons demanding that Agnew surrender the castle, garrison, and all military stores. Agnew refused. The siege settled into a grinding standoff. The government soldiers could hold the thick-walled castle, but they could not break out, and their food was running low.

On 19 March, Agnew gambled. He sent a mounted messenger to reach the Earl of Crawford, who was supposed to be commanding cavalry and Hessian troops somewhere in the Perth or Dunkeld area. The gamble appeared to fail immediately -- a short time later, a Jacobite was spotted riding the messenger's horse, and Agnew's men assumed the worst. What they did not know was that the messenger had been shot at while riding, had fallen from his horse, but had escaped on foot. Limping through hostile territory, he managed to make contact with Crawford's forces. Meanwhile, inside Blair Castle, the garrison inched toward starvation. There was nothing to do but hold on and wait for relief that might never arrive.

On 1 April, word reached the garrison that Lord George Murray and his men had departed. Murray had received orders from Prince Charles Edward Stuart to bring his forces north to Inverness, where the Jacobite army was concentrating for what would become its final stand. The following day, the Earl of Crawford arrived with cavalry to relieve Agnew's starving garrison. The siege had lasted two weeks. Fifteen days later, at Culloden on 16 April, the Jacobite cause was destroyed. Lord George Murray fought in that final battle and went into exile afterward. The Royal Scots Fusiliers who had endured the siege also fought at Culloden -- but on the government side. Blair Castle still stands in the Highland Perthshire landscape, the white-walled baronial seat of what is now the Atholl Estates. It carries no visible scars of the siege, but it holds the distinction of being the last castle in the British Isles to endure one -- a fitting end to a tradition that stretched back to the medieval era, played out in the dying days of the last Jacobite rising.