Christina of Holstein-Gottorp was Queen of Sweden as the second wife of King Charles IX. She served as regent in 1605, during the absence of her spouse, and in 1611, during the minority of her son, King Gustav II Adolph.

Charles IX, also Carl, reigned as King of Sweden from 1604 until his death. He was the youngest son of King Gustav I and of his second wife, Margaret Leijonhufvud, the brother of King Eric XIV and of King John III, and the uncle of Sigismund, who became king both of Sweden and of Poland. By his father's will Charles received, by way of appanage, the Duchy of Södermanland, which included the provinces of Närke and Värmland; but he did not come into actual possession of them till after the fall of Eric and the succession to the throne of John in 1569.