|Title(s)||High Steward of Highgarden|
|Book(s)||The World of Ice & Fire (mentioned)|
Unlike his elder brother, Gareth was of a more bookish bent and never achieved knighthood, choosing to serve as a royal steward instead. He and his son Leo performed their duties so well that the Gardeners made the office of High Steward hereditary.
- The World of Ice & Fire, The Reach: House Tyrell.