Career
Not to be confused with Agnes of Babenberg
Born to margrave John I of Brandenburg (d 1266) and Brigitte of Saxony. Married on 11 November 1273 to King Eric of Denmark at Schleswig. The marriage was probably agreed upon during Eric"s captivity in Brandenburg in the 1260s.
Tradition claims that Eric was released from captivity on his promise to marry Agnes without a dowry.
Denmark and Brandenburg, however, had a long tradition of dynastic marriages between them. The details of her regency are not known more closely, and it is hard to determine which of the decisions were made by her, and which was made by the council.
Peder Nielsen Hoseøl was also very influential in the regency, and she is likely to have received support from her family. In 1290, she financed a granted lime painting in the church Saint Bendt"s Church in Ringsted, which depicts her in a dominating way.
Her son was declared of legal majority in 1293, thus ending her formal regency.
Married in 1293 to count Gerhard II of Holstein-Plön (d 1312) with whom she had the son John III, Count of Holstein-Plön. She died on 29 September 1304, and was buried in Denmark.