Eysteinn Ásgrímsson was at the Abbey of Þykkvabær [is; de] until 1343, when he was sent to prison for beating up the abbot and possibly also for breaking his vow of chastity.
After returning to Norway in 1360, Eysteinn died the following March at the Helgisetr monastery in Niðarós (Trondheim).
[1] Lilja ("the lily", in medieval Christian imagery symbolizing purity and thus also the Virgin Mary), is generally attributed to Eysteinn and is the best known and possibly the best of the medieval Icelandic poems that adapted the complex structure and diction of skaldic poetry to Christian subjects.
[2] Eysteinn avoided both complicated kennings and loan-words as far he could, modifying the skaldic tradition on classical models based on the Christian ideal of claritas as enunciated by St. Thomas Aquinas, and rather than dróttkvætt, composed the poem in the hrynhent meter, which was closer to Latin hymnody and was subsequently nicknamed liljulag after the poem.
[2] The poem was emulated in the 15th century and an edited version included in the 1612 Icelandic Protestant anthology Vísnabók [is].