|The World of Ice & Fire (mentioned)
Archmaester Hagedorn is an Archmaester of the Citadel. He has put forth the theory that the centaurs that, according to ancient tales, inhabited the eastern grasslands of Central Essos were no more than mounted warriors as perceived by tribes who had not yet learned to tame and ride horses. His views are widely accepted at the Citadel despite purported "centaur skeletons" that occasionally appear in grotesqueries.
- The World of Ice & Fire, Beyond the Free Cities: The Grasslands.