Hvitserk is attested to by the Tale of Ragnar's Sons (Ragnarssona þáttr). He is not mentioned in any source that mentions Halfdan Ragnarsson, one of the leaders of the Great Heathen Army that invaded the Kingdom of East Anglia in 867, or vice versa, which consequently led some scholars to suggest that they are the same individual with Hvitserk being only a nickname.
After having avenged his father together with his brothers, he went to Gardarike (Garðaríki). Hvitserk also pillaged with the Rus. He was, however, opposed by such a large foe that he could not win. When asked about how he wished to die, he decided to be burned alive at a stake of human remains.
- "Ragnar Lodbrok och hans söner". Heimskringla.no. Retrieved March 25, 2016.
- "Hvitsärk". Nordisk familjebok. Retrieved March 25, 2016.
- Per G. Norseng. "Gardarike". Retrieved March 25, 2016.
- Войтович Л.В. Чи був Рагнар Лодброк на руських землях? // Україна в Центрально-Східній Європі. — Вип. 16. — К., 2016. C. 93-107.
- "Ubbe - Vikings Cast | HISTORY". HISTORY. Retrieved 27 March 2018.