Willas Tyrell

Willas Tyrell, is an unseen character in Game of Thrones. He has only appeared in the House Tyrell family tree issued by HBO. He is the eldest son and heir of Mace Tyrell, the Lord of Highgarden.

Background
Willas Tyrell is the eldest son of Mace Tyrell and Alerie Tyrell. He is the Heir of Highgarden. He has two younger brothers Garlan and Loras and one sister Margaery.

In the books
In the A Song of Ice and Fire novels, his family remains the same. Willas suffered a crippling injury to his leg in his adolescent years from a tournament accident while he was facing Oberyn Martell in a joust. Though this has increased the animosity between the Tyrells and the Martells (who have been bitter enemies for many generations prior to the incident), Willas himself is relatively calm about the injury and does not blame Oberyn, acknowledging that it was an accident and not his fault, and even befriending Oberyn to an extent.

The men of House Tyrell in the current generation tend to be well-meaning but not very intelligent, yet Willas is considered an exception to this. Willas is often noted as a studious, well-educated, and kind, and is renowned for breeding the finest hawks, hounds, and horses in the Seven Kingdoms.

Willas is unmarried, despite being a valuable marriage prospect as heir of the Reach. He hasn't married yet because the Tyrells are holding out for the best possible match to forge a marriage alliance. In A Storm of Swoards, Olenna and Margaery plot to have Willas marry Sansa Stark; as she is desperate to escape King's Landing, they are certain she will accept despite the age difference and his disability (the Tyrells, of course, want Sansa because she is the key to the North). In the series, Willas has not been mentioned on-screen, and it is Loras that the Tyrells plan to marry to Sansa.