Lord of Highgarden
From Asoiaf
The Lord of Highgarden rules the Reach. The current lord is Mace Tyrell
Highgarden belonged to the Kings of the Reach. When Mern, the last king, perished on the Field of Fire his steward Harlen Tyrell to Aegon the Conquerer. Aegon granted Highgarden and dominion of the the Reach to Harlen.