He was vicar of Österhaninge and then priest in Uppsala. He was canon of Strängnäs Cathedral from 1342 and dean of Uppsala Cathedral from 1356. He was a supporter of King Albrekt (c. 1338–1412) who appointed him chancellor. In 1365, Birger Gregersson is mentioned in the Diplomatarium Fennicum. In 1366, Birger Gregersson was elected archbishop of Uppsala diocese. He is considered one of the most important Swedish writers in the Middle Ages. [3][4]
He wrote a biography of Saint Birgitta (c. 1303–1373) and hymns to her and in honor of 12th-century missionary Saint Botvid (died ca 1120).
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