Christina was the daughter of King of Sweden Gustavus II Adolphus Wasa and, from the day of her birth at Stockholm, was considered as the heir to the throne. In 1630 Protestant Sweden became involved in the Thirty Years’ War. In November 1632, at the battle of Lützen, a Protestant victory, King Gustav was killed, and, at nearly six, Christina inherited the throne. In December 1644, at eighteen, Christina was officially coronated Queen of Sweden, but refused marriage with Charles Gustav Palatine, one of her cousins. She helped to bring an end to the Thirty Years’ War by supporting a theological resolution that unified the Protestant religions.

The “Minerva of the North” began to question Descartes through letters written by Pierre Chanut, one of Descartes’ friends and a minister of France to the Swedish government. In February 1647, Descartes answered Christina's questions: “What is love? Does the natural light by itself teach us to love God? Which is worse if immoderate and abused, love or hatred?” (AT IV 601, CSMK 306). Then Christina asked Descartes how to reconcile Christian religion with the hypothesis of an infinite world. He replied with the distinction between the “infinite,” reserved for God alone, and the “indefinite” world (AT V 51, CSMK 320) (see infinite versus indefinite). In September and November 1647, Christina asked Descartes’ views about “the supreme good understood in the sense of the ancient philosophers.” With his answer to the queen, Descartes sent a letter to Chanut, including the copy of his letters to Princess Elisabeth on Seneca and the ancients, and a “little treatise on the Passions,” a forerunner of the Passions of the Soul (AT V 81–88, CSMK 324–27). Having begun to read the Principles of Philosophy in French, Christina invited Descartes to Sweden (February 27 and March 6, 1649), and Descartes left Holland on September 1, 1649.