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 apparently a member of the Yngling clan (mentioned in later Norse and Anglo-Saxon literature, such as Beowulf). 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.