In the misty dawn of the ancient North, before the borders of kingdoms were etched in blood and parchment, the land of the Swedes was ruled by a king named Gylfi. He was a man of great curiosity and even greater hospitality, known for welcoming travelers who could regale him with tales of the unknown world or wisdom from the realms of the gods. One such traveler arrived at his court in the guise of a wandering woman, though she was in truth the goddess Gefjon, one of the Aesir who possessed the gift of foreknowledge and a sharp, calculating wit. Gefjon had come from the halls of Odin in Asgard, and she moved with a grace that suggested she walked upon the air as much as the earth. King Gylfi, charmed by her presence and her eloquent speech, offered her a reward for the entertainment she provided his court. In a gesture of expansive generosity—perhaps fueled by a desire to impress the mysterious visitor—he told her that she could take for her own any portion of his land that she could plow within the span of one day and one night.
Gylfi assumed that even the strongest of women, with the finest team of oxen in the kingdom, could only hope to turn a few acres of soil in such a short window. He did not realize that Gefjon was not bound by the limitations of mortals. Gefjon accepted the challenge with a subtle smile. She did not seek out the local livestock of the Swedish farmers. Instead, she journeyed far to the north, into the frozen, jagged wilderness of Jötunheim, the land of the giants. There, she sought out a certain giant with whom she had previously conceived four sons. These sons were not men, but creatures of immense power, born of a divine and primordial union. Through her enchantments, Gefjon transformed her four sons into gargantuan oxen, beasts of such scale that their breath could mist the valleys and their hooves could crack the very foundation of the mountains. Their hides were thick as iron, and their eyes burned with a cold, blue fire that spoke of their giant heritage.
Gefjon returned to the court of Gylfi with her monstrous team. The king, seeing the massive oxen, felt a pang of apprehension, but he was a king of his word and could not retract his offer. As the sun began to dip toward the horizon, marking the start of the allotted day and night, Gefjon set the plow. This was no ordinary wooden implement; it was a tool forged with the strength to cut through the deep crust of the world. She yoked her four sons to the beam and stood behind them, her hands steady on the handles. With a cry that echoed like thunder across the Swedish plains, she urged the team forward. The oxen put their shoulders into the yoke, and the earth began to groan. It was not merely the topsoil that the plow turned; it was the very bedrock of the Swedish interior. The sound was a deafening roar of grinding granite and tearing roots, a sound so loud it woke the birds in far-off Finland and sent the wolves of the deep woods scurrying for cover.
Throughout the night, Gefjon drove her sons with relentless energy. They plowed with such ferocity that the earth behind them did not simply turn over—it was severed. They cut a deep, wide swathe across the land, moving toward the western sea. The power of the oxen was so great that they began to pull the entire mass of the earth they had encircled away from the mainland. King Gylfi watched from his high towers, his jaw dropping in disbelief as he saw a significant portion of his realm being literally dragged toward the ocean. The oxen’s hooves dug deep into the clay and stone, leaving behind a massive, jagged hole in the center of the Swedish landscape. Gefjon did not stop to rest; she knew the value of the king’s promise and intended to maximize the gift. By the time the first rays of the morning sun began to light the sky, the oxen had reached the coast. They did not stop at the water’s edge. They waded into the deep, dragging the massive island-sized piece of land behind them through the waves of the Baltic Sea.
Gefjon directed the oxen to a spot in the sound between what is now Sweden and the peninsula of Jutland. With one final, Herculean effort, the oxen settled the land into the sea, where it took root and became the island of Zealand. This new land was fertile and rich, and Gefjon established it as her own domain, eventually marrying the king Skjöldr and founding a line of Danish kings. Meanwhile, back in Sweden, the king was left to contemplate the enormous void Gefjon had left behind. The great pit, carved out by the plow and the sheer force of the giant-oxen, quickly filled with water from the surrounding springs and rivers. This vast body of water became Lake Mälaren, though some storytellers in the centuries that followed claimed it was the even larger Lake Vänern, noting that the geographical contours of the lake and the island of Zealand matched each other with suspicious precision. The jagged bays of the lake were said to correspond exactly to the capes and headlands of the new island.