Question: Who fathered Helena Sverkerdotter who is a princess of the country where Brent Lagerberg's band formed?

full_context: Document 1: Bengt Lagerberg: Bengt Lagerberg (born 5 July 1973), is best known as the drummer in the Swedish rock band The Cardigans. He is currently living in Malmö.
Document 2: Yolanda of Poland: Blessed Yolanda of Poland (also known as Helen; 1235 – 11 June 1298) was the daughter of King Béla IV of Hungary and Maria Laskarina. She was the sister of Saint Margaret of Hungary and Saint Kinga (Cunegunda). One of her paternal aunts was the great Franciscan saint, Elizabeth of Hungary.
Document 3: Hep Stars: The Hep Stars were a Swedish rock group, formed in 1963 in Stockholm. During 1965-66 the band was the most successful of contemporary 1960s Swedish pop groups performing in the English language. Outside The Nordic Countries the band is best known as a launching point for the keyboard player and composer Benny Andersson, who went on to enjoy worldwide success with ABBA.
Document 4: Marie Bergman: Marie Bergman (born November 21, 1950 in Stockholm) is a Swedish singer. Between 1969 and 1972, she was a member in the pop group Family Four, which represented Sweden at the Eurovision Song Contest in 1971 and 1972. She started her solo career in 1974. She has during the years released 13 own-written records and 2 jazz albums and has received numerous awards. In 1994 she again represented Sweden at the Eurovision, this time with Roger Pontare, setting a record as the singer who has represented Sweden at the ESC the most times. This was equalled by Carola Häggkvist in 2006. Marie has performed at the Roskilde Festival four times.
Document 5: The Cardigans discography: The Cardigans are a band from Sweden. They have released 6 studio albums which in total have sold about 15 million copies worldwide. This is a list of their album and single releases.
Document 6: Helen of Sweden (13th century): Helen of Sweden ( 1190 – 1247, Swedish: "Helena") was a Swedish princess and abbess, daughter of King Sverker II of Sweden and the mother of Queen Catherine of Sweden. She was Abbess of Vreta Abbey.
Document 7: Mikael Stanne: Bengt Mikael Stanne (born 20 May 1974) is the vocalist & one of the lyricists (also previously rhythm guitarist) for the Swedish melodic death metal band, Dark Tranquillity and the ex-vocalist for Swedish power metal band HammerFall.
Document 8: Mats Rådberg: Mats Rådberg, born 8 June 1948 in Brännkyrka Parish in Stockholm, Sweden is a Swedish country singer, guitarist, composer and architect scoring several chart successes in Sweden during the 1970s and 80s. He is well known for working together with the country band Rankarna under the name "Mats Rådberg & Rankarna". He also participated at Melodifestivalen 1977 with the song "Du och jag och sommaren", written by Tomas Ledin, which ended up 10th.
Document 9: The Cardigans: The Cardigans are a Swedish rock band formed in Jönköping, Sweden, in 1992 by guitarist Peter Svensson, bassist Magnus Sveningsson, drummer Bengt Lagerberg, keyboardist Lars-Olof Johansson and lead singer Nina Persson. The group's line-up has been very stable, the only change being that their post-hiatus shows since 2012 have been with Oskar Humlebo on guitar instead of Svensson.
Document 10: Helén murder: The Helén murder () is a sadistic murder of 10-year-old Helén Nilsson in Hörby, Sweden, in March 1989. The murderer, Ulf Olsson, the so-called Helén man ("Helén-mannen"), was convicted in April 2005, having been found after a DNA test in 2004.
Document 11: Friends (Swedish band): Friends was a Swedish "dansband" or pop group formed in 1999 and made up of Stefan Brunzell, Tony Haglund, Kristian Hermanson, Nina Inhammar, Kim Kärnfalk and Peter Strandberg. They were put together from auditions on the reality television show Friends på turne ("Friends on Tour"), made by Bert Karlsson for TV4. The show was a success and Friends competed on Melodifestivalen 2000, reaching second place. They won Melodifestivalen 2001 with "Lyssna till ditt hjärta" and represented Sweden at the Eurovision Song Contest 2001 with the English version of the song, "Listen to Your Heartbeat" wearing sexy, tight, leather fitted clothing. Prior to the Eurovision performance, the Swedish delegation was forced to pay royalties to the team behind "Liefde is een kaartspel", an earlier Belgian entry, making the song the first admitted case of plagiarism in Eurovision history.
Document 12: Lovefool: ``Lovefool ''is a song written by Peter Svensson and Nina Persson for The Cardigans' third studio album, First Band on the Moon (1996). It was released as a single on 14 September 1996 in the United Kingdom and internationally on 5 October 1996. It was released as the album's lead single in 1996 and became the Cardigans' first international hit single, topping the Billboard Hot 100 Airplay chart and making appearances on six other Billboard charts. In 1997, the song found international success, peaking at number two on the UK Singles Chart and finding moderate success on some other European charts. The single also topped the charts in New Zealand, and was certified Gold in Australia.
Document 13: Best Of (The Cardigans album): Best Of is a greatest hits album by the Swedish group The Cardigans, released in Europe in January 2008. It contains twenty-one singles and album tracks. There is also a double-CD version with rare tracks and B-sides. Both versions of the album contain no new songs, though some tracks had previously been released only in the UK or Japan.
Document 14: Victoria, Crown Princess of Sweden: Victoria, Crown Princess of Sweden, Duchess of Västergötland (Victoria Ingrid Alice Désirée; , born 14 July 1977) is the heir apparent to the Swedish throne, as the eldest child of King Carl XVI Gustaf. If she ascends to the throne as expected, she will be Sweden's fourth queen regnant (after Margaret, Christina and Ulrika Eleonora) and the first since 1720.
Document 15: Helvis of Ibelin: Helvis of Ibelin (after 1178 – before 1 June 1216) was a daughter of Balian of Ibelin and his wife, Maria Komnene, who was the dowager Queen of Jerusalem. Helvis was a member of the House of Ibelin. She was Lady of Sidon by her first and second marriage.
ground_truth: Sverker II of Sweden
sub_queries: Bengt Lagerberg >> member of Answer: The Cardigans
What country released The The Cardigans ? Answer: Sweden
Who fathered Helena Sverkersdotter of Sweden ? Answer: Sverker II of Sweden