18 May - Eric was King of Sweden from about 1156 until his death on May 18, 1160, when his reign was marked by the first legendary attempt to convert the pagan Finns. According to the "Vita Santi Erici" written by the Bishop of Västerås, Israel Erlandsson in the 14th century, he organised a crusade in Finland.

Eric, however, soon had to face opposition from the son of Sverker I of Sweden; Karl, who was proclaimed king by the whole of Götaland as early as 1155/1158. He is furthermore attacked by the Danish suitor Magnus Henriksson. Surprised in Uppsala by the latter while attending mass on Ascension Day, he is killed on 18 May 1160 and is considered a martyr, thus becoming the patron saint of Sweden: "Erik den Helige".

The late king, who was very pious, had also promoted Christianity in his country and improved the lot of women. He was the founder of the house of Erik, which alternated with the house of Sverker on the throne of Sweden until the middle of the 13th century.