The Franco-Dutch War had begun two years earlier as a French lightning strike. In the spring of 1672, Louis XIV's armies overran most of the Dutch Republic in weeks. Grave, sitting on the Meuse in what is now North Brabant, fell to Turenne's troops on 5 July without much of a fight. The advance only stopped when the Dutch opened their dikes and turned Holland into a shallow sea - the famous Water Line. Then the calendar turned against the French. Spain, the Holy Roman Empire, and Lorraine joined the war. By 1674, French armies had been pulled out of one Dutch town after another. Only two remained: Maastricht to the south, and Grave on its quiet bend of the Meuse, cut off and surrounded by enemy country.

Chamilly turned Grave into what contemporaries called a hedgehog fortress, all spines and angles. When Lieutenant-general Carl von Rabenhaupt's Dutch army finally arrived on 25 July, the trenches would not advance. French gunners knew their ranges. The Meuse itself was an obstacle. The Dutch tried diverting the river Raam to drain the moat - it helped, then a French sortie pushed them back. Menno van Coehoorn, the most celebrated fortress engineer in the Dutch Republic, rode out to advise the besieger. Rabenhaupt, 71 years old and stubborn, ignored him. The summer dragged into autumn. Bombs fell. The walls of Grave still stood.

Two hundred kilometres to the southwest, William III of Orange had just fought the bloody, inconclusive Battle of Seneffe against Conde. His Austrian co-commander de Souches had sabotaged the campaign with obstructionism. William stripped him of command and, frustrated, took 10,000 troops and rode to Grave instead. He set up headquarters in Wychen Castle and assumed the siege. Inside the walls, Chamilly was apparently flattered - the famous prince had come personally to break him - and he resolved to be worthy of the opponent. He was. William's reinforcements achieved no more than Rabenhaupt's old guns had. The fortress, by now half rubble, would not yield.

It was Louis XIV himself who broke the stalemate. From Versailles, the Sun King wrote to Chamilly: the position made no strategic sense any more, abandon it. After a brief truce and negotiation, Chamilly capitulated on 27 October on generous terms. William, who had come to respect the man across the wall, let the garrison march out with the honours of war - colours flying, drums beating, weapons shouldered. The day after the surrender, William attended a thanksgiving service in St Elizabeth's church, sitting in his battle-stained uniform while his court preacher, also booted and spurred, gave the sermon. The civilian casualties inside Grave were never counted. The suffering, the chroniclers wrote, was indescribable.

Measured against the grand allied plan of 1674 - 120,000 soldiers, three war fronts, the liberation of the Spanish Netherlands - capturing one small ruined town on the Meuse was a meagre return. Yet it mattered. With Grave's fall, every patch of the Dutch Republic except Maastricht was back in Dutch hands. More than that, the siege marked the moment when the war stopped being a French sprint and became a grinding stalemate of attrition. Armies were getting bigger, casualties higher, and neither side was tired enough yet to make peace. For William of Orange, still only 23, Grave was a lesson in the patience and brutality of siege warfare - lessons he would carry to Ireland, to the Boyne, and eventually to the English throne.