According to Snorri, Ragnvald was the son of jarl Ulf Tostesson. He was also the foster-son of Þorgnýr the Lawspeaker. Through his aunt Sigrid the Haughty, he was the cousin of Swedish King Olof Skötkonung. He was married to Ingeborg Tryggvasdotter, daughter of Tryggve Olavsson, son of Olaf Haraldsson Geirstadalf and grandson of King Harald Fairhair. 
When Olaf Haraldsson became king of Norway in 1015, a war erupted with Sweden and Norwegians forces had pillaged in Västergötland. But then Norwegian King Olaf proposed to the Swedish princess Ingigerd Olofsdotter, the daughter of Sweden's King Olof Skötkonung. This would result in peace and a royal alliance which would favor Ragnvald who was related to both parties.
However, at the Thing at Gamla Uppsala, Ragnvald and his foster-father Þorgnýr the Lawspeaker had to persuade King Olof Skötkonung to promise his daughter to King Olaf, whom he did not like. When the Swedish king failed to deliver his daughter, Ragnvald realized that he was in trouble. He has not only fallen out of grace with the Swedish king, but he could also expect the revenge of the Norwegians.
During a visit by the skald Sigvatr Þórðarson, Ragnvald learned that Prince Yaroslav I the Wise of Kievan Rus' had proposed to Ingigerd, and so he developed the idea that King Olaf should marry Astrid Olofsdotter, an illegitimate daughter of Olof Skötkonung, who was staying with Ragnvald. Sigvat promised to deliver the proposal and the Norwegian king accepted. Ragnvald delivered Astrid at Sarpsborg in Norway and she married the King Olaf after Christmas of 1019.
King Olof Skötkonung was now so upset that he intended to hang Ragnvald at the next Thing. However, when Ingigerd Olofsdotter married Yaroslav I the Wise, she received Staraja Ladoga (Aldeigjuborg) and Ingria (Ingermanland) as a wedding gift from Yaroslav. Ingigerd managed to arrange that Ragnvald became the jarl of both Staraja Ladoga and Ingria. Consequently Olof Skötkonung let Ragnvald depart with Ingigerd in the summer of 1019.
Married to Ingeborg Tryggvasdotter. Children:
He has been considered to have fathered king Stenkil, with Astrid Nialsdotter from Norway. However this is based on later Icelandic sources, and the identification of Ragnvald with Ragnvald the Old of Hervarar saga.
Ragnvald is mentioned in the skaldic poem Austrfaravísur, ascribed to Sigvatr Þórðarson, skald of King Olaf Haraldsson of Norway (Olaf the Holy), who had been on a diplomatic mission to Sweden. This poem is quoted in the 13th century sagas Fagrskinna and Snorri Sturluson's Heimskringla. In addition to the poem, Fagrskinna only briefly mentions Ragnvald, while Heimskringla contains a more elaborate account of him. This 13th-century prose text is not considered historically reliable. Fagrskinna's account of Olaf the Holy's betrothal to Ingigerd, and eventual wedding with Astrid, differs significantly from the account in Heimskringla. In Fagrskinna's account, Ragnvald is not given a prominent role in the proceedings.
- Winroth 1995–1997:616
- Claus Krag. "Tryggve Olafsson". Norsk biografisk leksikon. Retrieved May 1, 2018.
- Knut Are Tvedt. "Olof Skötkonung". Store norske leksikon. Retrieved May 1, 2018.
- "Ingegerd". riksarkivet.se. Retrieved May 1, 2018.
- Per G. Norseng. "Ragnvald Ulfsson". Store norske leksikon. Retrieved May 1, 2018.
- "Astrid". riksarkivet.se. Retrieved May 1, 2018.
- "History of Staraya Ladoga". Staraya Ladoga. Archived from the original on April 6, 2005. Retrieved May 1, 2018.
- "Ingermanland Chronicle". ingermanland.nu. Retrieved May 1, 2018.
- The entry Stenkil in Larsson 2000:33
Stenkil anses ha varit son till Ragnvald jal i Västergötland. Translation: Stenkil is considered to have been the son of earl Ragnvald in Västergötland.
- Lagerquist 1997:41
Den nye kungen hette Stenkil och den ganska kortlivade dynasti han grundade kallas efter honom den stenkilska. Enligt senare isländska uppgifter var han son till jarlen Ragnvald i Västergötland och Astrid Nialsdotter från Norge. Translation: The name of the new king was Stenkil and the rather shortlived dynasty that he founded is named the House of Stenkil after him. According to later Icelandic reports, he was the son of the earl Ragnvald in Västergötland and Astrid Nialsdotter from Norway.
- Larsson 2002:154–157
[...] ingenting om Ragnvald den gamle eller den norska hövdingadottern Astrid som var Stenkils föräldrar enligt den fornisländska Hervararsagan. [...] Och lika lite kan jag få veta ifall Stenkils far Ragnvald var identisk med västgötajarlen med samma namn, som det ofta påstås i den historiska literaturen - en hypotes som i och för sig också skulle leda till släktskap med den gamla kungaätten genom att Ragnvald enligt sagorna var kusin till Olof Skötkonung. Translation: [...] nothing on Ragnvald the Old or the Norwegian chieftain's daughter Astrid who were Stenkil's parents according to the Old Icelandic Hervarar saga. [...] And just as little can I be informed whether Stenkil's father Ragnvald was identical to the Västergötland jarl by the same name, as it is often stated in history books - a hypothesis which, as it were, would lead to kinship with the old dynasty through the fact that Ragnvald according to the sagas was the cousin of Olof Skötkonung.
- Larsson, Lars-Ove (1993, 2000). Vem är vem i svensk historia, från år 1000 till 1900. Prisma, Stockholm. ISBN 91-518-3427-8
- Larsson, Mats G (2002). Götarnas Riken : Upptäcktsfärder Till Sveriges Enande. Bokförlaget Atlantis AB ISBN 978-91-7486-641-4
- Lagerquist, Lars O. (1997). Sveriges Regenter, från forntid till nutid. Norstedts, Stockholm. ISBN 91-1-963882-5
- Winroth, Anders (1995–1997) "Ragnvald Ulfsson", Svenskt Biografiskt Lexikon, volume 29, page 616.
- Wisén, Theodor, revised by Erik Brate (1915), "Ragnvald Ulfsson", Nordisk familjebok, volume 22, 913–914