Sophie was born in Wismar in Mecklenburg as the only child to Duke Ulrik III of Mecklenburg-Güstrow and Elisabeth of Denmark, who was the daughter of Frederik I of Denmark. We have only limited knowledge of Sophie’s childhood, but in 1571, she takes her place in Danish history when she becomes engaged, at just 14 years of age, to her cousin the 37-year-old Danish king Frederik II.

The wedding took place the year after the couple’s engagement, on 20 July 1572, at Copenhagen Castle. Despite the age difference, sources suggest that their marriage was harmonious. In his personal journal, Frederik II calls her his ‘Soffye’, and he describes their relationship and life together in affectionate terms. As queen, Sophie’s behaviour was exemplary. She stayed in the background and out of politics, as was expected of a queen. She collected folk songs and was interested in natural science, and she made several visits to the astronomer Tycho Brahe at his observatory Uraniborg on the island of Hven. Over a 10-year period, the couple had eight children, including their son Christian (IV).

Queen Sophie had no political influence while Frederik II was alive, but that changed after his death, in 1588. At that point, the 31-year-old Queen Dowager took on a more prominent role, in part as the guardian of her under-age son, King Christian IV, with the power that this implied. Focused on securing a good future for all her children, Queen Dowager Sophie had big marriage plans for them. Among other liaisons, she had her second-eldest daughter, Anna, married to James VI of Scotland. This made Anna queen of Scotland and, later, of England. Seeking to secure her younger sons duchies in Schleswig and Holstein, the ambitious Queen Dowager soon clashed with the Council of State, which thought that she interfered too much. In 1594, she was banished to her dower residence, Nykøbing Castle, on the island of Falster. 

As a banished queen dowager, Sophie soon proved a tough-as-nails businesswoman and a competent administrator of her estates on the islands of Lolland and Falster. She rationalised and modernised the management of the estates, built mills and engaged in extensive trade. She also had the castle modernised, including having water laid on.  

Another lucrative branch of Sophie’s business activities was lending. Many European princes borrowed money from her. So did her son Christian IV, who repeatedly had to come to his mother to ask for a loan for his construction projects and costly wars. 

Thanks to her business acumen, Sophie’s was the wealthiest private individual in Northern Europe at the time of her death, at 74, in 1631. Her fortune was 5.5 million rix-dollars; an almost unimaginable sum in today’s money. However, this vast fortune soon disappeared in the hands of her main heir, Christian IV, who spent his inheritance on building projects, the wedding of his eldest son and the war against Sweden.

Queen Sophie lies buried beside her husband, Frederik II, in Roskilde Cathedral.  

In this portrait, painted by Hans Knieper, she is probably shown wearing her wedding gown and a crown of gold with white pearls.