She is the most famous daughter of Gustav I, known for a courtship scandal in connection with a sister's wedding and for a lengthy stay in England under Elizabeth I where her first child was born.

[1] After the death of her mother in 1551, she as well as her siblings were placed in the care of Christina Gyllenstierna and then under her aunts Brita and Martha Leijonhufvud before her father's marriage to Catherine Stenbock.

In 1556, she and her sisters were given a dowry of 100.000 daler, had their portraits painted and their personal qualities described in Latin by the court poet Henricus Mollerus and presented on the dynastic marriage market.

Ostfriesland was chosen because it was strategically placed toward Denmark, and because the Calvinistic Emden was a rival to Lubeck and a treaty could break the domination of the Hanseatic league in Sweden.

While staying at the residence of Prince Magnus in Vadstena Castle on the way, a great scandal erupted when John was discovered in Cecilia's chamber without his trousers.

[2] The 17 December, Catherine and Edzard were sent to Västerås Castle and placed under house arrest, while Eric and Cecilia were both recalled to Stockholm.

[2] In the summer of 1560, John was released after having been forced to swear before the monarch and the royal council that nothing sexual had taken place between him and Cecilia.

[2] The rules also banned the princesses from receiving supplicants and meddle in politics on their behalf, or to in any way interfere in affairs of state: the same year, Cecilia, Anna and Sophia had sent a letter of protest to Eric regarding his imprisonment of their brother John, something he had a very negative reaction to.

[2] Cecilia and her sister Anna were long supposed to be married to Louis of Palatine-Simmern, George John of Palatine-Veldenz or Poppo of Henneberg.

It is noted that the wedding was far less luxurious than that of her sister Anna, and that it seem to have taken place without much negotiation: the first contract had been signed as late as March the same year.

Cecilia traveled to England through Estonia, Prussia, Poland and Germany (without visiting the home of her consort) to Antwerp in the Spanish Netherlands.

[4] Cecilia's visit to England was part of an attempt to convince Queen Elizabeth I to marry her half-brother King Eric XIV.

Her greatest creditors were George North and John Diamond (also called Dymoch): she also used the doctor Cornelius Alnetanus who borrowed her money and pawned things for her.

[2] She was pregnant at this point, and when she finally reached Rodemachern (now Rodemack) her son was born handicapped, for which she blamed her creditors for the rest of her life.

The religious war in the Netherlands was ongoing and the troops of the Duke of Alba moved around the territory of her residence and occupied her dower lands, which caused her economic distress.

In 1569, the second half of Baden, Baden-Baden, was inherited by the underage nephew of her consort and placed under the rule of his Catholic relative Albert V of Bavaria, who treated the Protestants with brutality.

Cecilia, however, also came in conflict with John because she violated her permission by also attacking ships from friendly nations, such as Danish, which created tension between Sweden and Denmark.

[2] On 2 August 1575, her absent consort Christopher died, and her under age son Edvard Fortunatus formally succeeded him as Margrave of Baden-Rodemarchern, albeit in his absence with her in Sweden.

[2] However, upon the death of Christopher, her former in-laws had the documents which secured her rights confiscated and took control over her dower lands as well as the rule of the entire Baden-Rodemarchern officially as the guardians and regents of her son.

John III wished to make an alliance with Spain to prevent Denmark and Poland to interfere with the Swedish war against Russia.

John III suggested that Cecilia, being a Catholic, could be made governor in one of the Spanish lands in Europe, preferably Luxembourg.

[2] The alarm rang, and Cecilia and her retinue was captured by the guard and brought to John, which caused a great scene between the siblings.

Upon her return to Baden in 1579, Cecilia sought to take control over her dower lands and of Baden-Rodemachen from the relatives of her late consort in name of her son.

[2] The daughter, who was fathered by Eraso, was placed in the convent of Liethentahl by Edvard Fortunatus against Cecilia's will, and she was not allowed to see her again until 1622: she took the vows as an adult and is known only by her name as a nun, Charitas.

[2] In her struggle against the family of her late consort, she was supported by the papal legate Antonio Possevino, Eraso and John III: her other brother Charles IX, however, broke with her after the birth of Charitas.

[2] Cecilia lived on the income of her Swedish estate, but this was confiscated by John in 1585 after her opposition to his marriage with Gunilla Bielke.

Cecilia became a known diplomat when she courted various Catholic power holders on behalf of herself and her son in economical and political matters on constant journeys.

The perhaps most known slander against her was a story by Everhard van Reyd: he claimed that she hosted a brothel in Antwerp, and that her son had to drag her from it in her hair (1590).

Cecilia lived in a difficult situation, as she was forced to support herself by loans due to her lack of income and was often hunted by her creditors.

Cecilia Gustavsdotter died in Brussels on January 27, 1627 at the age of 86 and is buried beneath the floor of the church in Rodemack.