and not something connected with a particular family. Bergsveinn Birgisson says Ynglingatal is not a genealogy, but a poem about people from different clans. Not all sources agree; in Historia Norvegiæ, About Uplanders kings and Íslendingabók, several of the kings of other names than in Ynglingatal or are said to live on or be buried elsewhere. Finnur Jonsson said the various descriptions stem from the kings mentioned in Ynglingatal; all have different traditions handed down by word of mouth. He said Thjodolf's poem is an attempt at a synthesis of different oral traditions about different kings. Euhemerism According to Snorri, the Yngling stemmed from the gods Yngve-Frey and Odin. This kinship, a euhemerism, is not left in the poem; only Snorri's words support this. Finnur Jonsson said he thought this song originally contained several verses and started with Yngve. Religion historian Walter Baetke said Yngligatal was free of euhemerism—the notion of lineage of gods was added in the Christian era. Claus Krag said the first kings of the poem are historicized gods, and that the hypothesis of lost stanzas may be rejected. Historical accuracy Opinions differ on whether breedings were historical figures. If all the kings in this poem really existed, the first of them must have lived in the Migration Period. It is usually only the "Norwegian" part of Ynglings—from Halfdan Hvitbeinn—that scientists have tried to prove or disprove were real, historical persons. They partly reasoned that people in Norse times kept track of their genus for six generations, thus it is possible to follow Harald Fairhair's ancestors back to Halfdan Hvitbeinn. Norwegian historians and archeologists have traditionally held the Norwegian Ynglings to be historical people. Because of problems with dating, it is problematic to work out when these people might have lived. Are Frode, in the 1100s, was probably the first person who tried to convert the dates from relative time stamps to absolute chronological dates on the basis of Jesus' birth; the reckoning began to be used during the Middle Ages and is still in use. Are dated Harald Fairhair's birth to 848, and until the 1920s historians used Are's reckoning to calculate the composition time stamp for different people and events. In 1921 historian Halvdan Koht introduced generation counting and his method became the dominant one. In 1964, Icelandic historian Ólafía Einarsdóttir found the old Icelandic reckoning more accurate; with adjustments this has since been the