Mace Tyrell is a recurring character in the fourth and fifth seasons. He is played by guest star Roger Ashton-Griffiths and debuts in "The Lion and the Rose". Lord Mace Tyrell is the Lord of Highgarden and head of House Tyrell. He is the father of Loras and Margaery Tyrell, and the son of Olenna Tyrell. He initially supported Renly Baratheon's claim to the Iron Throne in the War of the Five Kings, but after Renly's death he successfully negotiated an alliance with House Lannister to support King Joffrey's claim to the throne, on the condition that his daughter Margaery would marry Joffrey, making her the new queen and giving House Tyrell the prestige of entering into the royal bloodline.