The Willaq Umu ("priest who recounts", hispanicized spelling Villac Umu) were the High Priests of the Sun in the Inca Empire.
This office (in some accounts) was created during the reign of Pachakuti.
By the end of the empire, the high priest was also the field marshals in war for the emperor.
The Sun God in Inca mythology was Inti, and the most important god amongst the pantheon the Inca people.
Malden MA: Blackwell Publishing, 2003