Question: Olof Skötkonung's mother appeared in what line of sagas?
Context: Eric the Victorious (Old Norse: "Eiríkr inn sigrsæli", Modern Swedish: "Erik Segersäll") (c. 945?  – c. 995) was the first Swedish king (c. 970–995) about whom anything definite is known.  Whether he actually qualifies as King of Sweden has been debated, as his son Olof Skötkonung was the first ruler documented to have been accepted both by the Svear around Lake Mälaren and by the Götar around Lake Vättern. Estrid (or Astrid) of the Obotrites (c. 979 – 1035) was a Viking age Swedish queen and West Slavic princess, married to Olof Skötkonung, the King of Sweden, c. 1000–1022, mother of King Anund Jacob of Sweden and the Kievan Rus' saint and grand princess Ingegerd Olofsdotter. This is a list of wars involving the Kingdom of Sweden.  There are legendary accounts of Swedish kings well into prehistory and they are mentioned by Tacitus in his "Germania", but St. Olof Skötkonung (995–1022) was the first ruler documented to have been accepted by both the Swedes around Lake Mälaren and by the Geats around Lake Vättern.  The modern state of Sweden considers itself to have been established on 6 June 1523 by the acclamation of Gustav Vasa as king which finally ended the Kalmar Union with Denmark, although the current Swedish constitution dates to 1974. Olof Skötkonung (c. 980–1022) was King of Sweden, son of Eric the Victorious and, according to Icelandic sources, Sigrid the Haughty.  He succeeded his father in c. 995.  He stands at the threshold of recorded history, since he is the first Swedish ruler about whom we have substantial knowledge.  He is also commonly regarded as the first king known to have ruled both the Swedes and the Geats. Husaby, near Kinnekulle, is a village belonging to Götene Municipality in the province of Västergötland, Sweden.  It is most known for the old stone church Husaby Church.  Olof Skötkonung, the first Christian king of Sweden, is rumoured to have allowed himself to be baptised at a well by the church in 1008. Ingegerd Olofsdotter of Sweden, also known as Irene, Anna and St. Anna (1001 – 10 February 1050), was a Swedish princess and a Grand Princess of Kiev.  She was the daughter of Swedish King Olof Skötkonung and Estrid of the Obotrites and the consort of Yaroslav I the Wise of Kiev. Sigfrid (Sigfried, Siegfrid, Siegfried, Sigfridus, Sigurd) (born unknown date in Glastonbury, England – 1045 in Växjö) was a Benedictine monk, bishop in Sweden and saint.  He converted king Olof Skötkonung in 1008.  His feast day is 15 February. The Catholic Church in Sweden was established by Archbishop Ansgar in Birka in 829, and further developed by the Christianization of Sweden in the 9th century.  King Olof Skötkonung (ca. 970-1021) is considered the first Christian king of Sweden. Sigrid the Haughty, also known as Sigríð Storråda, is a queen appearing in Norse sagas as wife, first of Eric the Victorious of Sweden, then Sweyn Forkbeard of Denmark.  Sigrid appears in many sagas composed generations after the events they describe, but there is no reliable evidence as to her existence as they describe her.  The figure of Sigrid appears mainly in late Icelandic sagas, while more contemporary sources such as Thietmar of Merseburg and Adam of Bremen instead claim that Sweyn was married to a Polish princess, identified as Świętosława.  Snorri Sturlason gives conflicting information and in one place says that Sweyn was married to Sigrid and in another that he was married to a Gunhild of Wenden. Estrid (Old Norse: "Æstriðr", "Ástríðr") was a rich and powerful 11th-century Swedish woman whose long family saga has been recorded on five or six runestones in Uppland, Sweden.  This Estrid was the maternal grandmother of the chieftain Jarlabanke of the Jarlabanke clan.  The family were rich landowners and belonged to the higher echelons of Swedish society, and she was probably named after Estrid of the Obotrites, who was the queen of Sweden, and the consort of Olof Skötkonung, at the time Estrid was born.  Her family saga has been the centre of a dramatisation at the Stockholm County Museum.
Answer: Icelandic