From A Wiki of Ice and Fire
|Title||Lord of Riverrun|
|Book(s)|| A Game of Thrones (Mentioned)|
A Storm of Swords (Mentioned)
When Aegon I Targaryen reached the Riverlands during the War of Conquest he found noble houses ready to fight for him. The reigning king, Harren the Black, was unloved by his vassal lords and soon found them arrayed against him in the field. The first house to abandon Harren was Lord Edmyn of House Tully. When Harren burned at Harrenhal and his line perished with him, Aegon granted Edmyn dominion over the Riverlands and required the other river lords to swear him fealty.