The long Baltic inlet at the heart of the Duchy of Schleswig, with the herring port of Flensburg at its head, where Margaret I of Denmark died aboard her ship on 28 October 1412 in the middle of her war to recover Schleswig from the counts of Holstein.
Flensburg Fjord is a drowned glacial valley running inland from the Little Belt approaches, deep, sheltered and ice-free for most of the year — one of the best natural harbours on the western Baltic. The town of Flensburg sits at its innermost tip, where the land routes down the Jutland peninsula meet the water.
This was not a frontier in the Middle Ages in the sense it later became. The fjord lay inside the Duchy of Schleswig, also called Sønderjylland, a Danish fief held by dukes whose loyalty to the crown was the central political question of the region for three hundred years. The modern border through the middle of the water dates from the plebiscite of 1920.
Flensburg was founded about 1200 by Danish settlers, and German merchants moved in soon afterwards; it received its town charter in 1284 and grew quickly into one of the principal towns of the duchy. The harbour handled herring above all — the Baltic herring fishery was the great food industry of medieval northern Europe — along with cattle driven down the Jutland ox road, and grain.
The town was never formally a member of the Hanseatic League, since Schleswig lay outside the Holy Roman Empire and inside the Danish realm, but it traded constantly with Hanseatic merchants and shared their shipping routes and commercial habits. Ships in the fjord could reach Lübeck in a day or two, which tied the region’s economy to the Wendish towns whatever its politics.
The quarrel that brought a queen to these waters was two centuries old. The counts of Holstein, from the Schauenburg family, had built up a hold on Schleswig through wardships, mortgages and grants during the weak reigns of the fourteenth century, and by 1386 the duchy had been formally enfeoffed to Count Gerhard VI, tying a Danish fief to a German county.
Margaret I, who had united Denmark, Norway and Sweden under her control and sealed the arrangement at Kalmar in 1397, set herself to recover it. She worked by purchase and litigation as much as by war, buying back estates and pressing the legal claim that Schleswig was a fief that must return to the crown, and by 1412 she and her heir Eric of Pomerania had the upper hand in the fighting.
In October 1412 Margaret sailed from Zealand to Flensburg to press the negotiations, which were going her way. She attended the talks, returned to her ship in the harbour, and was seized there by a sudden and violent illness. She died aboard on 28 October 1412, at fifty-nine. Plague is the usual explanation and is what the town’s own record states; contemporaries and later writers also suggested shock at the death of her commander Abraham Brodersson, and — without evidence — poison. She seems to have known she was dying, ordering thirty-seven marks paid to a nearby monastery for a perpetual mass for her soul.
Her body was taken to Sorø Abbey and buried beside her father Valdemar IV Atterdag. In 1413 Bishop Peder Jensen Lodehat removed it, against the monks’ wishes, to Roskilde Cathedral, where Eric of Pomerania gave her a three-day funeral; the point was to establish Roskilde as the burial church of the rulers of the union. Her alabaster tomb there was carved by the Lübeck sculptor Johannes Junge in 1423.
The recovery of Schleswig died with her. Eric of Pomerania fought on for decades without settling it, an imperial arbitration of 1424 found for Denmark and was ignored, and in 1460 the estates of Schleswig and Holstein chose Christian I of Denmark as their lord on terms that bound the two territories together and away from direct Danish rule. The question Margaret came to Flensburg to close stayed open until the nineteenth century, and then closed violently.
The fjord itself still does what it always did. Flensburg remains a port at its head, the Angeln shore is farmland, and small craft work water that a queen of three kingdoms died on.