Christianity penetrated into Sweden through the Benedictine Saint Anscarius, the "apostle" of the north," born in Picardy, France in 801. Following the baptism of King Olof Skotkonung (1008), missionary activity strongly picked up.
In the 11th century, the prayer of the Ave Maria was a favorite among the people and religious. It was recited along with the Our Father and the Creed at each predication; it was also frequently inscribed on tombstones  and church bells.
The feast of the Assumption was the first national holiday established in Sweden.
A custom very significant of the role the Virgin played, was the placing of Mary's crown (from the parish statue) on the head of new brides on their wedding day.
At Vadstena, Saint Bridget (1303-1373) founded a male order, and a feminine order which Jesus called, according to her mystical revelations, his "Mother's Monastery"  and which quickly became a Marian shrine of great influence.
During the reign of King Gustave I Vasa (1495-1560) Protestantism was introduced in Sweden. Catholics did not regain freedom of worship until the edict of tolerance of Gustave II in 1781.
Writers of the romantic wave, for example Verner Von Heidenstam (1859-1940), by affirming the importance of popular tradition, facilitated the preservation of the mediaeval religious patrimony and Marian devotion, with its emotional, artistic, and literary character.
In the 20th century, the convents of Stockholm and Vadstena became prominent ecumenical centers in that country.
Currently, Sweden doesn't have a national Marian shrine, but only some local pilgrimage destinations.
The church of Oskarstrom, erected in 1910 by Polish immigrants, gathers each year on the first Sunday in May, almost all the Catholics in the country, about 28,000 people led by their respective bishops.
On the feast of the Assumption, Catholics from all the parishes in Stockholm meet in Djursholm at the convent of the Sisters of the Order of St Bridget for a solemn procession and a liturgy in front of a replica of the Lourdes Grotto.
After 1952, many statues of Mary reintegrated into Lutheran churches. There the faithful leave flowers and candles in from of these statues in honor of Our Lady and the pastors have started preach about the Mother of God again.
 Simple Marian invocations were also found, such as: "May God and the Mother of God assist his spirit. May God help his spirit and his soul. May the Mother of God assist him more than he deserved."
 Saint Bridget, Revelations (X, 4)
Attilio GALLI, Madre della Chiesa dei Cinque continenti, Ed. Segno, Udine, 1997.