Guðrún Ósvífursdóttir is the main protagonist of the Medieval Icelandic Laxdœla saga, which recounts the history of the People of Laxárdalur. It is widely thought that the saga represents some historical fact. Guðrún was famed for her beauty and was married four times. Her marriages were foretold when she relayed four dreams to Gest to interpret, each represented one of the marriages to come. Her first marriage to Thorvaldr Halldorsson ended in divorce. It was a brief unhappy marriage, however after the divorce she acquired half of his estate.  Her second husband Thord Ingunnarsson drowned at sea. She gave birth to his son soon after, naming him Thord. 
After her second husband's death she was courted by the two foster-brothers Kjartan Óláfsson and Bolli Þorleiksson. Guðrún preferred Kjartan, but she gave herself to Bolli, because of a false rumour that Kjartan was engaged to Ingibjörg, the sister of King Óláfr Tryggvason. The two foster-brothers engaged in hostilities which ended with Bolli killing Kjartan, and Bolli being killed by Kjartan's kinsmen.
Her third son, Bolli Bollason, was born the winter after the killing of his father, and her second son Thorleik was only four at the time. They grew up in Helgafell, after his mother Guðrún exchanged homes with the renowned Snorri the Goði.
In 1020, Guðrún married for the fourth time, this time to Thorkell Eyjolffsson (urged to propose by Snorri), who became a great chieftain in his own countryside and took over the running of the household at Holyfell. Thorkell was fond of both his stepsons, but Bolli was regarded as "being the foremost in all things". Thorleik journeyed abroad to Norway, and stayed with King Olaf II for several months.
Guðrún constantly argued for revenge for the killing of her former husband Bolli Þorleiksson, but eventually her two sons made peace with the sons of Óláfr, Kjartan's kinsmen, at the Thorness Thing; it is not known how much money was exchanged in compensation as part of the agreement, but "both sides were thought to have gained in esteem from these affairs". To get Thorgils to help her have revenge she promised to marry no other man in the country, nor to marry abroad. When he returns successful she tells him that she is to marry Thorkel since he technically meets the requirements of their promise. He was not in the country at the time, and they would not be marrying abroad. Thorgils was not very happy about this turn of events.
Her father, Osvif died soon after the marriage, he was buried at a church Guðrún constructed.
The day Thorkell drowned at sea, Guðrún saw the ghost of him and his companions standing outside the church. They vanished but left a strong impression on her, she became the first Icelandic woman to learn the Psalter. Herdis often accompanied her on her nightly prayer excursions. One night Herdis had a dream that led them to a discovery of a prophetess buried beneath Guðrún's prayer spot.
Her son Bolli asked permission to marry Thordis, the daughter of Snorri the Godi. Guðrún approved on the union.
In her old age Guðrún was asked by her son Bolli which of the men in her life she loved most. She gave the cryptic response "To him I was worst whom I loved best," which answer, though accepted by her son, has sparked great debate among scholars as to whom she was referring. Guðrún was the first nun and recluse in Iceland, and she died and was buried at Helgafell.
- Translation in English by Muriel Press (The Temple Classics, London, 1899)
- Text with modern Icelandic spelling
- Laxdæla saga in an English translation by Muriel A. C. Press, 1899, from Project Gutenberg
Guðrún Ósvífsdóttir and Making 3 Wishes at Helgafell http://www.icelandicroots.com/helgafell-three-wishes-and-our-ancestors-3/