A pawn in the games of men
The birth of Margaret I, or Margrethe as she was known in Denmark, was already marked by challenging circumstances – her mother was a prisoner at Søborg Castle when Margaret arrived in March 1353.[[1]] The youngest of six children of Valdemar IV, King of Denmark, and his wife Helvig, her story is one of a remarkable and well-deserved rise to power.
At the age of six, this daughter of the House of Estridsen was contractually engaged[[2]] to the youngest son of Magnus Eriksson, King of Sweden and Norway. In reality, Valdemar was after Scania[[3]], which wasn't part of the agreement. In 1359, he decided to act on his urges and occupy Scania, angering Magnus and resulting in the termination of the engagement. Valdemar continued on his rampage nonetheless, taking Visby, while Magnus joined forces with the Hanseatic League to enforce a trade embargo on Denmark.
Meanwhile, Haakon VI – formerly betrothed to Margaret and now the king of Norway and Sweden[[4]] – was engaged elsewhere. As fate would have it, the ship transporting his wife was redirected by a gale to Denmark; if that weren't misfortune enough, the marriage was also pronounced illegal.[[5]] Eventually, Denmark and Norway were able to reach a truce, and Margaret was married to Haakon on 9 April 1363 in Copenhagen, aged 10.
Margaret, who, like St. Bridget, possessed the masculine quality of indomitability, was undoubtedly the strongest.
All the right moves
When she was of an appropriate age, Margaret left her home in Denmark to live and be suitably educated at Akershus in Oslo. Political happenings abounded – her brother, heir to the Danish throne, passed away; and her husband and father-in-law were deposed from the Swedish throne and replaced by Margaret's nephew, Albert of Mecklenburg, in 1364.

A son, Olaf, was born to her in 1370. He would go on to be pronounced King of Norway[[6]] upon Haakon's death in 1380. But when Olaf passed away seven years later, aged only 16, Margaret found herself the Queen.
She was more than equipped for the job, being of a smart disposition, well-trained and educated, and having ruled Denmark and Norway alongside her husband, and in her young son's stead. With two kingdoms secured and stable, Margaret turned her attention to Sweden, where rebellions were rising against the king.
The Swedish nobility called on her help, and she responded by invading the country in 1388, becoming its ruler the following year after several battles. The captured King Albert hired the Victual Brothers to counter-attack, and when he was released in 1395 on a promise to pay a fine within three years, Stockholm was held as collateral by the Hanseatic League. In 1398, with Albert's failure to cough up, Stockholm was finally surrendered to the queen.
No ruler came after Queen Margaret equal to her, as there had been none before her to be compared to her.
Playing the long game
In 1389, Margaret chose her great-nephew, Bogislav[[7]], better known as Eric of Pomerania, as king of Norway. He was also accepted in Denmark and Sweden in 1396, though she would continue to rule until he came of age. Meanwhile, Margaret had published the Treaty of Kalmar proposing to unify the three countries, with a promise that they would retain their own borders and laws. The Kalmar Union lasted for over a century.
Though opinions on her motives have fluctuated, her legacy remains unquestioned. In addition to the church and workers, she stood up for women, and donated to charitable causes; she improved order, the economy, and recovered estates through reduction. She fought to regain lost territories, but remained neutral in larger European conflicts. It was during a war to regain Schleswig in 1412 that she died mysteriously on her ship in Flensburg.[[8]]
Historians have echoed this view. Hudson Strode wrote that,[[9]] "Margaret, who, like St. Bridget, possessed the masculine quality of indomitability, was undoubtedly the strongest. No male public official ever worked harder at his job. She used her constructive ability, her diplomacy, and her force of will to make the Union a success and to maintain the royal prerogative."
E.C. Otte, in a similar vein, believed that, “No ruler came after Queen Margaret equal to her, as there had been none before her to be compared to her."[[10]]
[[1]]: She was imprisoned by the king but the reasons are not clearly known.
[[2]]: Magnus allegedly wanted Denmark's support in a feud against his eldest son, Eric XII.
[[3]]: King Magnus had purchased many eastern Danish provinces, including Scania (Skåne), during a time of instability for Denmark.
[[4]]: He was the King of Norway since 1343, and co-ruled Sweden with his father from 1362-64.
[[5]]: Haakon was briefly married to Elisabeth of Holstein. When Elisabeth's ship landed in Denmark, she was taken prisoner until Margaret's marriage, and then released and spent the rest of her life in a convent. Helge Salvesen, “Elisabeth av Holstein", Store Norske Leksikon, https://snl.no/Elisabeth_av_Holstein
[[6]]: Margaret secured his spot as King of Denmark upon her own father's death in 1375, though the Mecklenburg's were after that too.
[[7]]: She adopted him, as well as his sister Catherine.
[[8]]: 28 October. Suspected causes of death range from shock and illness to poisoning.
[[9]]: Hudson Strode, Sweden: Model for a World. (Harcourt Brace, 1949), p. 130
[[10]]: E.C. Otte, Scandinavian History. 1874