On 13 January 1338, when Patrick Dunbar was away, the English laid siege to Dunbar Castle, where Lady Dunbar was in residence with her servants and a few guards. However, she was determined not to surrender the fortress even though the English were a vastly superior force of 20,000 men, and is said to have declared:
“Of Scotland’s King I haud my house, I pay him meat and fee, And I will keep my gude auld house, while my house will keep me.”
Women were known to take charge of castle or manor business while their husbands were away in the Middle Ages and defend it if need be, but the stand of Lady Agnes is one of the best remembered instances. Salisbury’s first attempt at taking the castle centered on catapulting huge rocks and lead shot against the ramparts, but this was met with disdain by Lady Agnes, who had one of her ladies-in-waiting dust off the ramparts with her kerchief.
The English were employing an enormous siege tower called a sow in an attempt to storm the castle, but the countess simply advised Salisbury that he should “take good care of his sow, for she would soon cast her pigs [meaning his men] within the fortress.” She then ordered that a boulder, which had been heaved on them earlier, be thrown down from the battlements and crushed Salisbury’s sow to pieces.
When one of the Scottish archers struck an English soldier standing next to Salisbury, the earl cried out, “There comes one of my lady’s tire pins; Agnes’s love shafts go straight to the heart.”
Unable to make progress through arms, Salisbury turned to craft. He bribed the Scotsman who guarded the principal entrance, advising him to leave the gate unlocked or to leave it in such a manner that the English could easily break in. However, the Scotsman, though he took the Englishman’s money, reported the stratagem to Agnes, so she was ready for the English when they made entry. Although Salisbury was in the lead, one of his men pushed past him just at the moment when Agnes’s men lowered the portcullis, separating him from the others. Agnes, of course, had meant to trap Salisbury, but she moved from stratagem to taunt, hollering at the earl, “Farewell, Montague, I intended that you should have supped with us, and assist us in defending the Castle against the English.”
At one point, having captured Agnes’s brother, John Randolph, 3rd Earl of Moray, the English threw a rope around his neck and threatened to hang him if Agnes did not surrender the castle. However, she merely responded that his death would only benefit her, as she was his heir. She was not in line for the earldom but was the heir to his lands along with her sister.
When supplies for her garrison began to run low after several months being cut off, Sir Alexander Ramsay of Dalhousie, who had earned a reputation for being a constant thorn in the English king’s side moved from Edinburgh to the coast with forty men. Appropriating some boats, Ramsay and his company approached the castle by the sea and entered the postern next to the sea. Charging out of the castle, the Scotsmen surprised Salisbury’s advance guard and pushed them all the way back to their camp.
After five months, Salisbury admitted defeat and lifted the siege on 10 June 1338. The triumph of a Scotswoman over an English army was written into a ballad, in which Salisbury says:
“Cam I early, cam I late, I found Agnes at the gate.”
The failed siege of Dunbar had cost the English crown nearly 6,000 English pounds and the English had gained nothing from it.
For centuries afterwards, Agnes’s defense of Dunbar Castle caught the attention of contemporary chroniclers and Scottish historians due to her bravery and might.