Ragnvald Heidumhære

Ragnvald Heidumhære (or Rognvald) was a legendary, possibly historic, petty king or chieftain of Vestfold in what is today Norway in the 9th century, according to Ynglingatal and to Ynglinga saga in Heimskringla. He was the son of Ragnar Lodbrok or Olaf Geirstad-Alf. His name Heiðumhæri could be translated as highly honoured
His greatest contribution to posterity was that he asked the skald Þjóðólfr of Hvinir to compose a poem about his ancestry. This poem is known as Ynglingatal and is not only one of the oldest, but also one of the most famous and debated of the Old Norse poems.
Þjóðólfr ended the poem with these lines:
Under the heaven's blue dome, a name
I never knew more true to fame
Than Rognvald bore; whose skilful hand
Could tame the scorners of the land, --
Rognvald, who knew so well to guide
The wild sea-horses through the tide:
The Heidumhære was the proud name
By which the king was known to fame.
The 13th century history Heimskringla, which used Ynglingatal as a source, makes him a cousin of Harald Fairhair, while late and dubious pedigree material assigns him a daughter Åsa Ragnvaldsdatter (Aseda Rognvaldsdatter), who married Eystein Ivarsson. As a purported ancestor to William the Conqueror, it would be through this connection with Ivarsson that the current British royal family traces its roots all the way back to the Yngling bloodline mentioned in, among other sources, Beowulf.