When Ansgar, the Apostle of the North, went to Sweden in 829, the Swedes were still heathen and the country contained many sacrificial groves and temples for the worship of Germanic pagan idols.

One of the bishops was Henry, who took part in the Crusade to Finland led by king Eric IX of Sweden and suffered martyrdom there in 1157.

In 1152 Cardinal Nicholas of Albano, later Pope Adrian IV, visited Sweden and held a provincial synod at Linköping.

The pious and energetic Archbishop Jarler and his successor Laurentius (1257–67), a Franciscan, constantly strove to elevate the clergy and to enforce the law of celibacy.

The cathedral of Uppsala, the most important church of Sweden and the largest in Scandinavia, was built by the French architect Etienne de Bonnuille in 1287.

Some were zealous pastors of their flocks, such as Jarler and others; some were distinguished canonists, such as Birger Gregersson (1367–83) and Olof Larsson (1435-8); others were statesmen, such as Jöns Bengtsson Oxenstierna (d. 1467), or capable administrators, such as Jacob Ulfsson Örnfot, who was distinguished as a prince of the Church, royal councillor, patron of art and learning, founder of the University of Uppsala and an efficient helper in the introduction of printing into Sweden.

Among the orders represented in Sweden were the Benedictines, Cistercians, Dominicans, Franciscans, Brigittines (with the mother-house at Vadstena Abbey) and Carthusians.

Still greater credit is due the members of the orders, both men and women, for their services in the intellectual training of the people of Sweden.

A Swedish Protestant investigator, Carl Silfverstolpe, wrote: "The monks were almost the sole bond of union in the Middle Ages between the civilization of the north and that of southern Europe, and it can be claimed that the active relations between our monasteries and those in southern lands were the arteries through which the higher civilization reached our country."