Acta sanctorum in Selio

Saint Sunniva
Late Gothic sculpture of Saint Sunniva from the Austevoll altarpiece (c. 1520, now in Bergen Museum).
Born	Ireland
Died	10th century Selja island, Norway
Venerated in	Roman Catholic Church Orthodox Church
Major shrine	Selje Abbey
Feast	July 8
Patronage	Diocese of Bjørgvin; Vestlandet

Saint Sunniva (10th century; Old Norse Sunnifa, from Old English Sunngifu) is the patron saint of the Norwegian Diocese of Bjørgvin, as well as all of Western Norway.

Sunniva was venerated alongside her brother Alban, who in Norwegian tradition was identified with Saint Alban, the Roman-era British saint.

Acta sanctorum in Selio is a Latin hagiography of saints Alban and Sunniva and their companions. It is believed to have been composed shortly after 1170. Oddr Snorrason made use of it in his Óláfs saga Tryggvasonar (originally in Latin but only extant in Old Icelandic translation), in a section known as Albani þáttr ok Sunnifu ("tale of Alban and Sunniva", also known as Seljumanna þáttr) Oddr's original work was composed in Latin but only survives in an Old Icelandic translation. The legend was also included in the later Óláfs saga Tryggvasonar en mesta. The tale is directly based on that in Acta sanctorum in Selio, and thus slightly younger, although likely still belonging to the 12th century.

According to the legend, Sunniva was the heir of an Irish kingdom, but had to flee when an invading heathen king wanted to marry her. She and her brother Alban (post-Reformation accounts add two sisters, called Borni and Marita) and their followers settle the previously uninhabited islands of Selja and Kinn in Norway during the rule of the pagan Jarl Hákon Sigurðarson (r. 962–995). Their Norwegian neighbors on the mainland suspect the Christians of stealing sheep and complain to Jarl Hákon. Hákon arrives on Selja with a group of armed men, intending to kill the inhabitants. When the Christians realize what is happening they hide in caves on the island and pray to God to collapse the caves to spare them from being ravaged by Hákon and his men. The caves collapse and kill all the Irishmen.