Märta Eriksdotter (Leijonhufvud) was an eminent politician and landowner.

Märta Eriksdotter was born into mainstream politics in the 1500s, as the daughter of Erik Abrahamsson (Leijonhufvud), knight and member of the Council of the Realm, and his wife Ebba Eriksdotter (Vasa), King Gustav Vasa’s second cousin. Precious little is known about her childhood. Her father, who at least in 1514–1518 was registered in Lo (Loholm) in Långared parish in the province of Västergötland, was executed in the Stockholm bloodbath in 1520, the same year as she was born. She probably spent her first years at Loholm Castle. There is however information that Märta Eriksdotter was born at Ekeberg manor at Lillkyrka in Närke. According to lists over the assets of the mother and children, it appears that they owned around 500 farms spread over almost the whole of Sweden, since Ebba Eriksdotter (Vasa) had become the head of the family after her husband’s death. Märta Eriksdotter’s older sister Margareta married King Gustav Vasa in 1536.

The historian and chronicler Johannes Messenius reports that it is thought that Margareta was betrothed to the knight and marshal Svante Stensson Sture before she married the King. Märta Eriksdotter married Svante Stensson Sture, but contemporary sources do not corroborate this triangle situation as it is reported in later literature. Märta Eriksdotter must have been 18 years old when the wedding was held in Nyköping Castle in 1538. Svante Sture was the son of the previous regent Sten Sture the younger and Kristina Nilsdotter (Gyllenstierna), and one of the most eminent men of his time. Märta Eriksdotter and Svante Sture had 15 children.

Both Märta Eriksdotter and her sister thus belonged to the top social group in the realm. They kept in touch with each other by letter. Letters have also been preserved from among others their niece Queen Katarina Gustavsdotter (Stenbock), married to Gustav Vasa in his third marriage. These letters provide unusually good insights into Märta Eriksdotter’s adult life.

Gustav Vasa’s death in 1560 and his son’s accession to the throne the year after were to have great effect on Märta Eriksdotter’s life. Her husband had been one of Gustav Vasa’s trusted and was made a duke by King Erik XIV, but the new king’s suspiciousness towards sections of the top nobility was to have disastrous consequences. In May 1567 the king called parliament together, but also made several of the nobles come before the High Court. Under torture, they admitted things that confirmed the king’s suspicions that among others Märta Eriksdotter’s husband Svante Sture and two of her sons were mixed up in a conspiracy. According to the historian Ellen Fries, she was at Tullgarn Castle when she was reached by the message that her husband and sons had been imprisoned, at which she then tried to travel to Svartsjö Castle. According to the clergyman and historian Anders Fryxell, Märta Eriksdotter was imprisoned in Svartsjö Castle and later on the farm Nybble. When the prisoners were moved from Svartsjö to Uppsala Castle, she was imprisoned in a house in the town.

Märta Eriksdotter worked urgently on her case using the means she had at hand, among others by trying to influence Erik XIV’s beloved Karin Månsdotter to speak for her to the king. Several of the letters written by Märta Eriksdotter to Karin Månsdotter have been preserved, and they bear witness to a woman who was not only well informed about the political games of her time, but also had a foreboding of great danger. In the letters, Märta Eriksdotter is adamant that she herself as well as her husband and sons only desired to serve the king. Her incessant attempts to rescue her family members are also evident in her letters to Princess Virginia – King Erik’s daughter outside wedlock – who at that time would have been only about 8 years old. Märta Eriksdotter called herself “a poor miserable woman” and bade that their enemies might not “gain that power over my poor old husband and me that they so clearly desire”. In letters to both Princess Viriginia and Karin Månsdotter, she prays too that the king will fulfil his promise to allow her to be with her husband.

Whether or not any conspiracy actually existed is unclear, but the king’s certainty was sufficient for him to rush into the room where Märta Eriksdotter’s son Nils (born in 1543) was being held prisoner and stab him with a knife. The king is then thought to have ordered the executions of Svante Sture and the other son, Erik (born in 1546), as well as some other noblemen in what has gone down in history as the Sture murders. Märta Eriksdotter’s brother Sten Leijonhufvud, who had also been imprisoned, survived since King Erik is thought to have given the order to spare the nobleman Sten, and it was unclear which Sten he meant. The Sture murders have been interpreted as expressions of King Erik’s developing madness and they led to Märta Eriksdotter, as one of the relatives, being awarded a significant sum of money in compensation. In addition, she was allowed to retain Svante Sture’s duchy, expanded by the inclusion of Västervik and Stegeholm Castle, and she played a very important role in the political aftermath. In connection with the funeral in Uppsala Cathedral on 4 July 1567, Märta Eriksdotter had the bloody clothes (which can still be viewed) that her relatives had been wearing during the murders placed in a coffin besides the bodies. An open letter from the king circulated that a reconciliation between himself and ”Duke Svante’s survivor, the noble and honourable Lady Märta” had been agreed.

In September 1568, an uprising led to King Erik being deposed and Märta Erikdotter’s nephew Johan becoming king. In her position as a leading figure in the Sture clan, the new successor provided the possibility for her to remain at the absolute top of the realm. Märta Eriksdotter was also an enterprising landowner, who administered several important estates and counties and she was also gifted with an excellent sense of economy. When Johan had been made king, Märta Eriksdotter was careful to emphasise the great economic injustices she considered had been inflicted on the Sture clan. One of these was the service to the crown that had been imposed on Svante Sture. While a nobleman was usually compelled to donate a horse and rider, Svante Sture was compelled to donate 20, since his lands were so extensive.

From Västervik, Märta Eriksdotter ran a shipping company in which she owned her own ships. She also administered the county’s vast oak forests, and she was involved in several legal cases. Her personal characteristics have been presented in later literature as contrasting with her husband’s. She is described as resolute and powerful while he is supposed to have been mild and calm. One piece of information often presented is that she was therefore called ”King Märta”, but it cannot be substantiated in contemporary sources. Instead, most things indicate that Märta Eriksdotter demonstrated the kind of power that was expected of a noblewoman at that time, and that she, like many other women, has received similar epithets at a later date. By her contemporaries, she was referred to as the duchess of Västervik and the mistress of Hörningsholm.

Märta Eriksdotter died on 15 January 1584 at Stegeholm Castle. She is buried in the Sture chancel in Uppsala Cathedral.