House Tyrell traditionally held the title since the death of Mern Gardener and the extinction of his House during the War of Conquest, when Harlen Tyrell, the Steward of Highgarden, bent the knee to Aegon the Conqueror, but all prominent members of the house were killed after the Destruction of the Great Sept of Baelor and the Sack of Highgarden.
Ser Bronn of the Blackwater later offers to join Jaime and Tyrion Lannister with the forces of Queen Daenerys Targaryen, rather than assassinate them, should he be named Lord of Highgarden, a deal to which Tyrion reluctantly agrees.
After the Battle of King's Landing and the subsequent Great Council of 305 AC, Bronn was named to the position by Brandon Stark, the newly crowned Lord of the Six Kingdoms. He was additionally named Master of Coin, the post held by his predecessor Mace Tyrell.
In the books
In the A Song of Ice and Fire novels, there is no mention of House Tyrell actually being granted the title of Lord Paramount. Instead, the title of "High Marshal of the Reach" seems to be the equivalent. This difference between House Tyrell and other Great Houses is never touched upon.
|Lord:||None, extinct||Heir:||None, extinct|
|Title(s):||High Steward of Highgarden · Lord of Highgarden · Lord Paramount of the Reach · Warden of the South|
|Ancestors:||Garth Gardener · Harlen Tyrell · Lyonel Tyrell|
|Deceased members:||Luthor Tyrell · Mace Tyrell · Margaery Tyrell · Loras Tyrell · Olenna Tyrell · Tyrell lady · Alerie Tyrell|
|Household:||Mira Forrester · Sera Durwell|
|Overlord:||House Targaryen · House Baratheon of King's Landing (formerly) · House Gardener (formerly)|