When German forces swept into neutral Belgium in 1914, the refugees came with them. By the end of that first year alone, a million Belgians had crossed into the Netherlands. Many were fleeing the occupation; others were trying to reach unoccupied Belgian territory in the west, or France, or England, where they could enlist and fight back. King Albert I and Cardinal Mercier openly encouraged them. The German response, beginning in the spring of 1915, was to build a fence. Not symbolic wire, not a checkpoint barrier, but a continuous, electrified killing line stretching more than two hundred kilometres from Aix-la-Chapelle to the River Scheldt. The official German designation was Grenzhochspannungshindernis - High Voltage Border Obstacle. Locals called it something simpler. Dodendraad. The Wire of Death.

The dead were not soldiers. They were farmers, smugglers, mothers carrying children to relatives on the other side, young men who wanted to enlist, priests, brothers and sisters trying to reach each other. The methods of crossing read like a folk catalogue of desperation: pole vaulting over the wires, dragging extension ladders through the woods, digging tunnels, lashing porcelain plates to the soles of shoes in the hope that insulation might save them. Some succeeded. Many did not. Newspapers in the southern Netherlands carried near-daily notices about people 'lightninged to death' - a phrase that captured both the suddenness and the helplessness of it. The wire did not discriminate. Several Dutch citizens died too, accidentally drifting into it from the neutral side.

The Belgian-Dutch border had never really been one. Flemish-speaking villages on both sides intermarried, traded, celebrated weddings together, buried each other's dead. The wire cut all of that in half overnight. The most quietly devastating image from those four years is not of the people who died trying to cross, but of those who lived alongside it: funeral processions would walk to the fence and halt there, so that relatives and friends on the other side could stand at the wire and pray, and say goodbye, before the coffin turned back. The Germans did make concessions. People could pass through under guard for church services on market days and during the harvest. The fence skipped rivers. None of that helped a family separated by twenty metres of copper.

The wire was hated, and not just by Belgians. The Netherlands had entered the war hostile to Britain, a hangover from the Second Boer War, but the daily news of villagers killed at the border swung public opinion sharply against Germany. Smuggling, already a Flemish border tradition, became both more dangerous and more lucrative - a tin of butter or a sack of coffee was worth a king's ransom if you survived the crossing. Historians have since drawn the obvious parallel: the Dodendraad was the Iron Curtain a generation early, a sealed border policed by lethal force to keep a captive population from leaving. The comparison is not a stretch. The mechanism was almost identical. Only the politics behind it differed.

In October 1918, with the German lines collapsing in the west, the occupiers opened the wire and let French and Belgian refugees pour back through rather than clog their own supply roads. A few weeks later the armistice was signed and the power stations that fed the fence went dark. Villagers on both sides converged on the wire and tore it down by hand. There was, by all accounts, very little ceremony. Today almost nothing remains of the original fence. A few warning signs survive in local museums, and short reconstructed stretches stand at Hamont-Achel, Zondereigen, Molenbeersel, and in the De Maatjes nature reserve between Achtmaal and Nieuwmoer, where a wooden observation post called De Klot looks out over what was, for four years, a place where ordinary people came to die for the chance to walk a few hundred metres north.