Maria Eleonora of Brandenburg was Queen of Sweden from 1620 to 1632 as the wife of King Gustav II Adolph. She was born a German princess as the daughter of John Sigismund, Elector of Brandenburg, and Anna, Duchess of Prussia, daughter of Albert Frederick, Duke of Prussia.

Gustavus Adolphus, also known in English as Gustav II Adolf or Gustav II Adolph, was King of Sweden from 1611 to 1632, and is credited with the rise of Sweden as a great European power. During his reign, Sweden became one of the primary military forces in Europe during the Thirty Years' War, helping to determine the political and religious balance of power in Europe. He was formally and posthumously given the name Gustavus Adolphus the Great by the Riksdag of the Estates in 1634.