The war had already claimed Sweden's leader. On January 19, 1520, Regent Sten Sture the Younger was wounded fighting Danes on the frozen surface of Lake Åsunden near Bogesund. He tried to retreat to Stockholm but died two weeks later. The Swedish council, seeking peace, reached an agreement with Denmark: Christian II would become King of Sweden in exchange for amnesty for Sture's followers. But one person refused to accept this bargain. Christina Gyllenstierna, Sture's widow, took command of the resistance. She held Stockholm and key Swedish castles, rallying supporters from Dalarna and the capital itself while Danish forces occupied Uppsala.

The armies that met at Uppsala were mismatched from the start. The Danish force consisted of professional mercenaries from France, Scotland, and Germany - men who had made war their trade, equipped with the finest weapons and armor of the age. Opposing them stood Swedish peasants, poorly equipped farmers and townspeople fighting for their homeland. Approximately 7,000 combatants clashed on that holy day. The propaganda machines of both sides spun wildly afterward: Christina Gyllenstierna claimed victory for Sweden, while Christian II wrote to his German relatives that the Swedes had lost 12,000 men. Neither account can be trusted, but the mass graves tell their own story.

Five hundred years later, archaeologists discovered what the contemporary sources could not capture: the physical reality of medieval combat. The graves contained whole skeletons mixed with random limbs, articulated sections tangled with the commingled remains of multiple people tossed together without ceremony. From the 52 skulls examined, researchers calculated an average of 2.7 wounds per person - suggesting victims were struck repeatedly, either because they were overwhelmed by multiple attackers, because the Danes sought to ensure their enemies were dead, or simply because rage and battle-frenzy drove the killing beyond necessity. The lack of protective headwear among the Swedish dead speaks to the gap between the armies.

The Battle of Uppsala did not end the war. Christina Gyllenstierna continued her resistance through the spring and summer of 1520, but Stockholm eventually fell. Christian II was crowned King of Sweden on November 4, and three days later, the coronation festivities turned to horror. The Stockholm Bloodbath began - a mass execution of Swedish nobles, clergy, and supporters of the Sture party. Among those killed were several who had fought at Uppsala or supported the resistance. The Good Friday battle's casualties had been appalling, but the calculated slaughter that followed would reshape Scandinavian politics. Within three years, Gustav Vasa would lead a successful rebellion that ended the Kalmar Union forever.

Uppsala was Sweden's spiritual center - home to the archbishop and the ancient temple site at Gamla Uppsala nearby. That the battle occurred on Good Friday, the holiest day in the Christian calendar commemorating Christ's crucifixion, added a layer of religious significance that contemporaries would not have missed. Danish mercenaries killing Swedish peasants on the day of the Passion, in the shadow of the cathedral - the symbolism was dark and powerful. Today, Uppsala is a peaceful university city, its medieval past visible in the cathedral and castle but largely forgotten in daily life. Yet beneath the modern streets, the bones of 1520 remain, witnesses to the day when nothing was good about Good Friday.