Mary, Queen of Scots, was barely a year old in March 1544, and Scotland was fracturing around her cradle. The Treaty of Greenwich would have betrothed her to Prince Edward of England, knitting the two crowns together; the Parliament of Scotland had thrown it out. Henry VIII's response, history would later christen the Rough Wooing, a war of devastating cross-border raids meant to bully the Scots back to the negotiating table. Matthew Stewart, 4th Earl of Lennox, and William Cunningham, Earl of Glencairn, kept backing the English match anyway. That made them traitors in the eyes of the Regent, James Hamilton, 2nd Earl of Arran. Lennox wrote anxiously to Mary of Guise, the queen's French mother, offering to stand trial before his peers and protesting that men were murmuring he was the principal cause of disorder in the realm. He was buying time. Arran was already on the march.

Arran moved fast. Artillery and hand guns were sent west from Edinburgh Castle, and Bothwell Castle fell on 8 March. Lennox's men dug in at Glasgow Cathedral and the Bishop's Castle that crowned the hill above the town. Lennox himself, however, stayed safely behind the river walls of Dumbarton Castle. When the two armies met on Glasgow Muir, his absence may have mattered. The English messenger Edward Storye reported that after the battle Arran marched into Glasgow and laid siege to the Bishop's Castle on Wednesday 26 March. The gunner Hans Cochrane directed Arran's artillery against the cathedral and castle, the heavy iron balls hammering into walls built to outlast empires. A Glasgow barber-surgeon was hired to tend the wounded, the sort of practical mercy that war always seems to require.

When Lennox's garrison finally surrendered, gallows were raised on the street outside the Tolbooth. Sixteen or eighteen of the leaders were hanged there in front of the townspeople, an execution meant to be seen. According to Robert Lindsay of Pitscottie, writing decades later, the captains of the castle had been promised gold to surrender and were murdered for trusting the promise. Pitscottie laid the trick at the door of Cardinal Beaton. Among the dead on the moor was Arran's own Master of Household, killed on his master's winning side. There is something hollowing about that detail, the way a victorious army still goes home with empty places at its table. Three hundred is the number the chroniclers settled on; behind that round figure are individual lives, families in Glasgow and Kilmarnock and Renfrew waiting for news that would arrive carried by a stranger.

The Earl of Glencairn's eldest son, Alexander Cunningham, Lord Kilmaurs, and Lennox's brother Robert Stewart, Bishop-designate of Caithness, slipped out of Dumbarton Castle by night, working their way along the river Clyde before riding hard for England. Robert Boyd, whose charge had broken the day for Arran, was rewarded with his family lands and the restoration of the title Lord Boyd. In May, a second battle, the Battle of the Butts, was fought on the same moor between Arran and Glencairn; Glencairn's son Andrew died on the field. Lennox, unable to retake Dumbarton, sailed for England around 28 May. Ten years later, pardons were issued to many who had fought on his side, including Glencairn himself and George Hay, 7th Earl of Erroll. The war over the infant queen's marriage rumbled on for years, and Mary, when she was finally old enough to choose, married no Englishman at all.