Heimskringla Ynglinga Saga Sources

Þjóðólfr inn fróði (the Learned) from Hvinir was a poet of King Haraldr
inn hárfagri (the Fine-Haired). He composed a poem in honour of King
Rǫgnvaldr heiðumhæri (Nobly Grey), which is called Ynglingatal. Rǫgnvaldr
was the son of Óláfr Geirstaðaálfr, brother of Hálfdan svarti (the Black).
In that poem are named thirty of his paternal ancestors, and the death and
burial place of each of them is related. The one called Fjǫlnir was son of
Yngvi-Freyr, whom the Svíar worshipped for a long time afterwards. The
Ynglingar are named after him. Eyvindr skáldaspillir (Poet-Spoiler) also
enumerated the paternal ancestors of Jarl Hákon inn ríki (the Great) in the
poem that is called Háleygjatal, which was composed in honour of Hákon.
In that poem Sæmingr is named as a son of Yngvi-Freyr. There also the death
and burial place of each of them is related. The history of the Ynglingar is
written first according to Þjóðólfr’s account, and augmented according to
the account of learned men.


- Heimskringla, Prologue