All the sagas agree that Olaf eventually came to Kievan Rus', specifically the court of Vladimir I of Kiev. The version in "Heimskringla" is the most elaborate, but also the latest, and introduces elements to the story that are not found in earlier sources. It states that Olaf was born shortly after the murder of his father in 963, while other sources suggest a date between 964 and 969. The later dates cast doubt over Olaf's claim to be of Harald Fairhair's kin, and the legitimacy of his claim to the throne. Snorri Sturluson claims in "Olaf Tryggvson's saga" that Olaf was born on an islet in Fjærlandsvatnet, where his mother Astrid Eiriksdottir, daughter of Eirik Bjodaskalle, was hiding from her husband's killers, led by Harald Greycloak, the son of Eirik Bloodaxe. Greycloak and his brothers had seized the throne from Haakon the Good. Astrid fled to her father's home in Oppland, then went on to Sweden where she thought she and Olaf would be safe. Harald sent emissaries to the king of Sweden, and asked for permission to take the boy back to Norway, where he would be raised by Greycloak's mother Gunhild. The Swedish king gave them men to help them claim the young boy, but to no avail. After a short scuffle Astrid (with her son) fled again. This time their destination was Gardarike (Kiev), where Astrid's brother Sigurd was in the service of King Valdemar (Vladimir I). Olaf was three years old when they set sail on a merchant ship for Novgorod. The journey was not successful: in the Baltic Sea they were captured by Estonian vikings, and the people aboard were either killed or taken as slaves. Olaf became the possession of a man named Klerkon, together with his foster father Thorolf and his son Thorgils. Klerkon considered Thorolf too old to be useful as a slave and killed him, and then sold the two boys to a man named Klerk for a ram. Olaf was then sold to a man called Reas for a fine cloak. Six years later, Sigurd Eirikson traveled to Estonia to collect taxes for King Valdemar.