Swedish Queen Christina abdicated her throne in favour of her cousin Charles Gustav and converted to Catholicism.

Christina, a member of the House of Vasa, was Queen of Sweden from 1632 until her abdication in 1654. Her conversion to Catholicism and refusal to marry led her to relinquish her throne and move to Rome.

Charles X Gustav, also Carl X Gustav, was King of Sweden from 1654 until his death. He was the son of John Casimir, Count Palatine of Zweibrücken-Kleeburg and Catherine of Sweden. After his father's death he also succeeded him as Pfalzgraf. He was married to Hedwig Eleonora of Holstein-Gottorp, who bore his son and successor, Charles XI. Charles X Gustav was the second Wittelsbach king of Sweden after the childless king Christopher of Bavaria (1441–1448) and he was the first king of the Swedish Caroline era, which had its peak during the end of the reign of his son, Charles XI. He led Sweden during the Second Northern War, enlarging the Swedish Empire. By his predecessor Christina, he was considered de facto Duke of Eyland (Öland), before ascending to the Swedish throne. From 1655 to 1657, he was also Grand Duke of Lithuania.

The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.27 to 1.41 billion baptized Catholics worldwide as of 2025. It is among the world's oldest and largest international institutions and has played a prominent role in the history and development of Western civilization. The Church consists of 24 sui iuris (autonomous) churches, including the Latin Church and 23 Eastern Catholic Churches, which comprise almost 3,500 dioceses and eparchies around the world, each overseen by one or more bishops. The pope, who is the bishop of Rome, is the chief pastor of the church.

June 6 is the 157th day of the year in the Gregorian calendar; 208 days remain until the end of the year.