Jurgen Windcaller was the founder of the Greybeards, an ancient Nord war leader and Master of the Voice. He created the Way of the Voice. Later Jurgen Windcaller converted to pacifism and denounced use of the Voice for martial exploits. His philosophy prevailed, largely due to his unshakable mastery of the Voice -- his victory was sealed in a legendary confrontation, where he is said to have "swallowed the Shouts" of seventeen Tongues of the militant school for three days until his opponents all lay exhausted (and then became his disciples). Today, the most ancient and powerful of the Tongues live secluded on the highest peaks in contemplation.
His ghost now resides in the Hall of Valor in Sovngarde. He was the first to understand that the Voice should be used for the worship and glory of the gods, not for the glory of man. His mastery of the Voice overcame all opposition and he founded the Way of the Voice, passing down this knowledge to those who become the Greybeards.