Highgarden is an ancient seat of rule and the heart of chivalry in the Seven Kingdoms. Harlen Tyrell, hereditary high steward of the Reach, was granted Highgarden and dominion of the Reach by Aegon upon the death of King Mern at the Field of Fire. The Tyrells claim descent from the gardener king of the Age of Heroes through the female line (indicating their origin among the Andal invaders thousands of years before). Their motto is, “Growing Strong.”
Lord Mace Tyrell, Warden of the South, Defender of the Marches, High Marshal of the Reach, and member of the King’s small council, rules the house. He besieged Storm’s End while following the Targaryens during the War of the Usurper, but bent his knee after the Sack of King’s Landing. His heir is Willas, lame after an accident while a squire jousting against Oberyn Martell. Lord Mace’s favorite son is Ser Loras, called the Knight of Flowers, a prodigy of martial skill even at the age of fifteen.
After Robert’s death, Renly and Ser Loras fled to Highgarden where Renly married Margaery and proclaimed himself king. Coming towards King’s Landing with a huge host, King Renly created a Rainbow Guard with the seventeen-year-old Ser Loras as its Lord Commander. When Renly was killed, a fifth of the horse that had gone with him to Storm’s End returned with Ser Loras to Bitterbridge after Loras killed two of his fellow Rainbow Guard is his rage.
The Tyrells have made an alliance with the Lannisters, smashing Stannis’s host at the Blackwater. Lord Mace enjoys a seat on the small council, Ser Loras was made a member of the Kingsguard, and Margaery Tyrell is now betrothed to King Joffrey. However, Mace’s mother, Lady Olenna, did not care for the marriage match and conspired with Littlefinger to poison Joffrey at his own wedding feast. Now the Tyrells are pressing for Margaery to be wed to Tommen.