In the Middle Ages, continental culture, philosophy and science spread to Sweden through the Catholic Church, which also founded schools, Uppsala University, hospitals as well as monasteries and convents.

The Reformation in Sweden began in 1527 when King Gustav Vasa and his Riksdag of Västerås broke the full communion of the Swedish church with Rome, making it politically subservient to the kingdom.

On 21 May 2017, Pope Francis named Bishop Anders Arborelius, the Ordinary of Stockholm, a Cardinal, a first for the Catholic Church in Sweden.

In the 1770s, the prominent Liberal Anders Chydenius - himself a Lutheran priest - prevailed upon King Gustav III to legalise the immigration of Catholics (as well as Jews) into Sweden.

When Emperor Louis the Pious was visited in 829 by two envoyés of the Swedish king, who messaged that several in their homeland were willing to convert to the Christian faith, he appointed Archbishop Ansgar for the mission.

Ansgar and his assistant, the monk Witmar, followed with a convoy of merchants, but halfway they were attacked by vikings, and had to reach Birka on foot.

Archbishop Ansgar, sometimes called the "Apostle of the North", arrived in the town of Birka on an island in Lake Mälaren in 829 from the Archbishopric of Bremen, and founded ostensibly the first Christian parish in Sweden.

The first significant sign that Christianity had been established on a larger scale was the baptism of King Olof Skötkonungs circa 1008.

In a Papal document from 1120, Skara was mentioned, Liunga kaupinga (Linköping), Tuna (Eskilstuna), Strängnäs, Sigtuna, and Arosa (Västerås or possibly Östra Aros/Uppsala), all as episcopal sees.

She managed to have the pope recognise the establishment of the Bridgettines order, and a convent was founded, Vadstena Abbey.

Some of them are, besides Bridget, are Sigfrid of Sweden, and Helena of Skövde, but there were also local cults of for instance Catherine of Vadstena, Nils Hermansson, Ingrid of Skänninge, and Brynolf of Skara.

During the 16th century, King Gustav Vasa broke the relations with the pope, as did several northern European monarchies.

The process had its background in the reformers' criticism of Catholicism, but it was also due to a larger societal context, including attempts to foster a centralised military state under more powerful royal control.

Regarding the first, the conflict stood primarily at the Riksdag of Västerås in 1527, and the break with the pope through the abolition of the Canon law in 1536 under King Gustav Vasa.

Throughout the modern era, immigrants arrived from Catholic countries who only reluctantly made superficial professions of Lutheranism, although some might have been described as crypto-Catholics.

John III participated in Catholic eucharist and had extensive dialogue with the Holy See in Rome of having the Swedes returning to Catholicism, but these attempts were stranded.

After the death of King John III in 1592, Duke Charles was appointed acting regent (Swedish: riksföreståndare).

At the same time, the ideas of the Reformation were recognised along with the establishment of a national church in Sweden during the Uppsala Synod in 1593.

Due to the throne ascension of King Sigismund III and the establishment of the Swedish–Polish Union 1594-1599, the Protestant Reformation was halted, and religious freedom allowed.

Subsequent to Duke Charles victory in his War against Sigismund 1599, all Catholics were banned and exiled, enforced by death penalty.

After the death of King Charles IX in 1611, some legal suspensions were offered for ambassadors from Catholic countries and their relatives for them to live their faith, as for a few merchants and mercenaries.

For instance, in 1624, the Mayor Zackarias Anthelius and the royal secretary, Göran Bähr, both received the death penalty for converting to Roman Catholicism.

King Gustavus Adolphus' daughter and successor Queen Christina had Catholic clergy invited to her court.

In the 1720s, Catholic textile workers arrived, primarily from the Holy Roman Empire; these were granted limited freedom of religion.

Since 1873 it has been legal also for Sweden citizens to adhere to the Catholic Church without risking death penalty or exile.

The education typically lasts a total of seven years, covering studies in philosophy, theology, pastoral practical work, as well as spiritual and liturgical instruction.