Maria Romberg was born in 1697 in Sweden, into a society where women’s autonomy was severely limited by patriarchal customs and arranged marriages. At the age of 19, she was forced into a marriage with Anders Broberg, a merchant 27 years her senior, in the town of Borås. The union was reportedly unhappy from the start. Accounts from the time describe Broberg as violent, emotionally abusive, and given to excessive drinking. Even Maria's own stepfather publicly accused her husband of alcoholism and cruelty, suggesting the marriage was a source of considerable misery.

By 1719, Maria reconnected with her childhood friend Haqvin Wijndruf, a young man from one of Borås’s most prominent and wealthy families. Their romantic relationship quickly blossomed despite Maria’s marital status. The affair became common knowledge in the town, with various townspeople assisting in their correspondence, acting as go-betweens for their love letters. Broberg's reaction was one of fury and humiliation, and in 1722 he summoned two local vicars to lecture Maria about her behavior and duty as a wife.

These lectures and increasing scrutiny did little to dissuade Maria and Haqvin. The pair attempted to poison Broberg twice but failed. Eventually, Maria sought the help of Ingeborg "Romans Ingeborg", a cunning woman reputed for practicing folk magic and alleged to have carried out murders for hire. Ingeborg agreed to help Maria eliminate her husband.

Maria’s domestic life appeared to worsen, and according to testimony, the couple’s maid Karin Andersdotter was also abused by Broberg. Karin would eventually join the conspiracy. By 1724, the four conspirators had made several failed attempts to kill Broberg, including an aborted strangling. Each failed attempt only intensified their resolve.

On the evening of December 28, 1724, after yet another moral rebuke from the clergy, Maria Romberg finalized the plot to end her husband’s life. That night, while Anders Broberg slept in his bed, Maria, Ingeborg, and Karin entered his room. Ingeborg struck him repeatedly in the head with a blunt object until he died. They then staged the scene to appear as though Broberg had fallen and struck his head by accident.

However, the ruse was quickly detected. Upon inspection, local authorities suspected foul play. The case moved swiftly. Karin Andersdotter, the maid, was the first to break under questioning and confessed to the murder plot. When Maria learned of the confession, she admitted her role and urged Haqvin to do the same. Haqvin initially denied all involvement, claimed Maria had multiple lovers, and attempted to flee. He was apprehended, returned to custody, and ultimately confessed under pressure.

All four conspirators were put on trial. On February 23, 1725, Maria, Haqvin, Ingeborg, and Karin were all found guilty of murder and sentenced to death with varying forms of punishment. Maria was to be decapitated and her body burned. Haqvin Wijndruf was also decapitated, and his head nailed to a pole in public display—a symbol of shame for his once-prominent family. Ingeborg received the harshest sentence: her hand was first cut off, then she was decapitated and burned, likely as punishment for being a known purveyor of magic and for her role in multiple attempts. Karin, as the youngest and a servant, received the most lenient death sentence: simple decapitation and a burial.

On the morning of April 14, 1725, all four were executed. Maria Romberg was around 28 years old at the time of her death. The trial and execution sent shockwaves through Swedish society, not only for the sensational nature of the murder and the involvement of a woman of standing, but also because the affair marked the collapse of the influential Wijndruf family in Borås. Haqvin’s brother Andreas Wijndruf, a newly ordained priest, emigrated to North America just months after the execution, further severing the family’s influence in Swedish society.