From A Wiki of Ice and Fire
|Title||Hand of the King|
|Book||The World of Ice & Fire (mentioned)|
Edgar Sloane was a nobleman of House Sloane who served as Hand of the King for Jaehaerys II Targaryen.
As King's Hand, Edgar was an aged and seasoned man. Maester Yandel notes that he was exceedingly cautious.
Edgar served as Hand of the King for Jaehaerys II Targaryen, one of the many seasoned, older men serving the king. Upon the king's death, he was retired from office by Aerys II when the latter ascended to the Iron Throne and Ser Tywin Lannister, the heir of Casterly Rock, was named in his place.