In Quillette, Paul Lockhart recounts one of the early artillery successes in European siege warfare, the reduction of the English-held fortifications at Odruik:
Philip the Bold, duke of Burgundy, was a warrior’s warrior. Hawk-nosed, ambitious, and brash, Philip had been a soldier since childhood. He was still a smooth-faced boy of 14 when he fought alongside his father, King John II of France, in the battle of Poitiers in 1356. Like King John, he was taken prisoner by the English when Edward, the Black Prince of Wales, vanquished the French on the field at Poitiers. A decade later, the duke, always looking for an advantage over the Englishmen who had invaded his country, embraced a novel technology: gunpowder.
This mysterious Asian invention had been known in Europe for more than a century, and for nearly that long European armies had used it as a weapon of war — or, more precisely, as the substance that made another recent innovation, the cannon, work. So far, gunpowder artillery had not shown great promise. Cannon had been used as siege engines in European warfare at least as early as the 1320s. But for all the trouble and effort they demanded, they had not proven themselves to be much more effective than conventional siege weapons such as catapults and trebuchets, machines that used mechanical energy to hurl projectiles at castle walls. Certainly, the early cannon did not appear to be effective enough to justify their cost, which was substantial.
But Philip the Bold saw promise in the new weapons, especially the huge siege guns that came to be known as bombards, and in 1369 he began to invest heavily in them. France and England were then locked in the on-again, off-again series of dynastic conflicts known today as the Hundred Years’ War (1337–1453). In 1377, when Duke Philip’s brother and sovereign, King Charles V of France, ordered him to attack the English in the Calais region, the duke answered the call, bringing with him more than 100 new cannon, including one monster of a gun that fired a stone cannonball weighing some 450 livres (around 485 pounds).
One of the duke’s intended targets was the English-held castle at Odruik, built with stout masonry walls and surrounded by a thick layer of outworks. Odruik would be a tough nut to crack. Its defenders seemed to think so, too, and were confident that they could hold out against Duke Philip’s army, even as the duke’s men began to put their huge siege cannon into position in full view of the castle walls.
The first few shots from Philip’s siege-battery hammered Odruik’s outer walls into dust. Soon, the stone cannonballs were sailing through the walls as if they weren’t there; soon after that, the outer walls actually weren’t there. After Philip’s guns had fired a grand total of about 200 rounds, much of Odruik’s once-proud walls lay in ruin, and before the duke could send his men through the breach and into the castle, Odruik’s defenders capitulated.
Philip the Bold’s triumph at Odruik in 1377 was a harbinger of things to come, a revealer of unsettling truths. Gunpowder artillery had been used in sieges before, but Odruik was its first overwhelming and clear-cut victory over a castle. The siege of Odruik demonstrated that — when the guns were big enough, and when there were enough of them — cannon were more powerful than any siege engine yet invented, and could knock down castles in a matter of hours. What happened at Odruik would be repeated over and over again at castles throughout continental Europe and the British Isles through the remainder of the Middle Ages and beyond.
It was one of the accepted “rules” of war that a besieged town that surrendered before the beseiging army conducted an infantry assault would be spared from sack … the theory being that once the fortifications had been overcome, the final outcome was not in doubt and the defenders lost no honour from the surrender. You can certainly understand why the citizens of the defended town would be eager to avoid the plunder and rapine of an assaulting army once the walls were breached.