The elderly matriarch of House Tyrell, Lady Olenna has been a master of court politics and intrigue par excellence throughout her life. She's also known for her wit and sarcasm. As a result, Lady Olenna is popularly nicknamed the Queen of Thorns, in reference to her House's sigil and her cutting barbs. In many ways she is the de facto head of House Tyrell at the time of the War of the Five Kings and appears to hold a great deal of influence over the Reach.
Olenna Tyrell is the widow of Lord Luthor Tyrell and the mother of Mace Tyrell, the current Lord of Highgarden, Warden of the South, Lord Paramount of the Reach, and head of House Tyrell. She is the grandmother of his children Loras and Margaery. She was born into House Redwyne, one of the most prominent and powerful vassals of House Tyrell.
In her youth, Olenna Redwyne was engaged to a member of House Targaryen, as it was "all the rage" at the time; it was her sister Viola whom Luthor Tyrell was expected to marry. The night before Luthor was to propose to Viola, Olenna snuck into his chamber and seduced him, leaving him "unable to walk downstairs" the next day to propose; the thought of marrying a Targaryen and his "ludicrous silver hair" did not appeal to her.
Although Olenna consistently referred to Luthor as an oaf, she was genuinely fond of him, and confided to Margaery that she had some difficulty accepting his death after his body was delivered to her.
At some point following her granddaughter's engagement to Joffrey Baratheon, Lady Olenna moved to King's Landing, most likely to work behind the scenes to cement the Tyrells' position. Reasoning that Sansa Stark is the best person to ask about Joffrey, Olenna invites her to a lunch of lemon cakes (Sansa's favorite) and cheese (her own favorite). Sansa is initially too scared to speak, but after much prodding, Sansa blurts out that he is a monster. Lady Olenna is disappointed but unsurprised at the revelation.
A few days later, Lady Olenna is sought out by Varys, who finds her terrorizing her granddaughters over their unimaginative veneration of House Tyrell's unimaginative sigil. Olenna throws a mild barb or two at him before demanding his reasons for seeking her, aware of the Spider's reputation. They discuss Sansa, and Littlefinger's interest in her. Varys warns her just how dangerous Littlefinger really is, Olenna agrees that Sansa must be kept away from him. When Varys is about to offer a solution, Olenna dismisses him, saying that the solution is rather obvious.
Hoping to mitigate the potential costs of an extravagant royal wedding, Tyrion Lannister meets with Lady Olenna. She lectures him on the importance of an extravagant royal wedding, particularly if it, along with the large amounts of grain and livestock brought to King's Landing from the Reach, prevents the Smallfolk from ripping the nobles apart. Lady Olenna also reminds Tyrion of the thousands of Tyrell troops now assisting the Lannisters in the current war, and that the royal house traditionally pays for a royal wedding. Nonetheless, she agrees to pay half the costs of the wedding itself provided the celebrations are not cut short. Lady Olenna expresses disappointment in Tyrion's character– she had hoped to encounter the lecherous, mischievous imp of legend, and not a "browbeaten bookkeeper"– and in Podrick Payne's serving abilities before departing.
After he finds out about the plan to wed Loras to Sansa, Tywin Lannister, determined to thwart this plan, which would hand control of the North to the Tyrells, meets with Lady Olenna. He instead offers to marry Loras to Cersei (both of them pretend that there is no outstanding plot). Olenna, claiming herself an expert on the subject, declares Cersei too old, and will soon be undergoing "the change". Tywin counters by mentioning Loras' homosexuality. Olenna bluntly confirms that her grandson is a "sword swallower", and cheekily asks whether Tywin ever experimented in his youth, a suggestion the Hand haughtily refutes. Olenna makes light of what amounts to "a discreet bit of buggery", and hints at the rumors of incest between Cersei and Jaime, which, she notes, currently have Westeros at war. Tywin says that neither he nor Olenna care what other people think of them (an assertion she refutes). He proceeds to call her bluff by threatening to name Loras to the Kingsguard, thereby exchanging the uncertainty of Cersei's childbearing status for the certainty of House Tyrell's extinction. Olenna snaps Tywin's quill in half and graciously concedes defeat.
Lady Olenna attends the wedding of Tyrion Lannister in the Great Sept of Baelor. She stands near the feet of the Mother's statue with her grandchildren and is not amused when Joffrey embarrasses Tyrion by hiding his footstool. At the wedding feast, Olenna, muses on now-extremely complicated in-law relationships between Margaery, Loras, Cersei and Tyrion, prompting Loras to storm out and Margaery to give her a withering look. Later on, she regards Tywin and Tyrion's latest argument with amusement.
Olenna assists Margaery in picking out a necklace for her upcoming wedding. She selects the finest of those on offer, noting affectionately that it is similar to one she received from her husband on her 51st name day. Olenna chucks the piece over the rampart and into Blackwater Bay and orders the Tyrell handmaidens to canvas every jeweler in King's Landing; the girl who brings her the best necklace can keep the next best for herself. After they are left alone, Margaery sardonically suggests letting Joffrey pick out the necklace which, knowing him, will likely consist of severed sparrow's heads. Olenna cautions Margaery to mind what she says, even with her. They are shortly interrupted by Brienne of Tarth, whose appearance prompts a rather melodramatic reaction from Olenna.
At Joffrey's wedding, Olenna speaks with Sansa, expressing her condolences for the fate of her family and inviting her and Tyrion to visit Highgarden. She toys with Sansa's hair in a grandmotherly fashion during the exchange. She chides Tywin Lannister that the Tyrells are paying half of the cost of the extravagant wedding, and that the Lannisters may need to turn to the Tyrells for financial support again, due to the crown's increasing war debts, particularly to the Iron Bank of Braavos. She later witnesses the poisoning of King Joffrey, and is the among those who call for help.
When Margaery questions as to whether or not she is actually the queen now that she is also a widow, Olenna advises her not to press the issue for a while. Olenna is optimistic that she is closer to being Queen now than she ever was when she was with Renly Baratheon. She is also relieved that Margaery is now free from Joffrey's torture and opines that Tommen Baratheon will be a better match – one the Lannisters can't afford not to make.
Some time later, Olenna and Margaery discuss Olenna's impending departure, and whether the Lannisters will consent to Margaery's match with Tommen. Olenna tells her how she seduced Luthor, and says Margaery she must do the same with Tommen, or else Cersei will turn the boy against her. Luckily for Margaery, Cersei is distracted by Joffrey's recent death and accusing her innocent brother of the crime. Margaery states that Olenna cannot know Tyrion's innocence for sure, to which Olenna claims she can. Olenna explains to a shocked Margaery that she could not bear to leave her granddaughter in the hands of "that beast", leading Margaery to realize that it was Olenna who poisoned Joffrey.
Olenna departs King's Landing some time soon after Joffrey's funeral, but conveniently before Tommen's coronation. She claims that she has grown to hate the long walks through the Red Keep's gardens that seem to take up much of her time in the capital.
Mace Tyrell is one of the many lords present at Tywin Lannister's wake
Some time later, Lord Mace attends a meeting of the Small Council. Like Grand Maester Pycelle and Kevan Lannister, he is somewhat disturbed to see that Cersei has appointed Qyburn to replace Varys. He nonetheless hastily puts himself forward as a candidate for Hand of the King, but Cersei declares that he is instead to be jointly appointed Master of Ships and Master of Coin.
Mace Tyrell is present during the wedding ceremony of Tommen Baratheon and his daughter Margaery. Later, Mace and the rest of the Small Council listen to the High Septon demand the arrest of all members of the Sparrows and execution of the High Sparrow. He is shocked to hear a man who is the head of the Faith of the Seven was visiting a brothel
In a Small Council meeting Mace reveals that the Iron Bank has called in one tenth of the Crown's debts. When asked by Cersei, Mace admits that the Crown can not pay back more than half of the demanded sum. When Mace offers that House Tyrell could lend the needed money to the Iron Throne, Cersei politely refuses, stating that the Tyrells have already given too much. She then tasks Mace with personally travelling to Braavos to negotiate better terms with the Iron Bank. She also tells Mace that the king, concerned for his father-in-law's safety, has assigned Ser Meryn Trant to escort Mace to Braavos. Mace and Meryn leave immediately, prompting Pycelle to state that the Small Council grows smaller and smaller.
After arriving in Braavos, he is greeted by Tycho Nestoris who welcomes him in the name of the Iron Bank. On the way to the Iron Bank, he talks with Tycho about the harvest in the Reach and King Maegor III who once outlawed moneylending. Unbeknownst to all of them, they are followed by Arya Stark, who recognised Ser Meryn. Arriving at the Iron Bank, Mace admires the facade of the enormous building, stating that the men of the Iron Bank are the world's best gamblers much to Tycho Nestoris' disapproval. After an unspecified time of negotiation, Tycho tries to bid farewell to Mace (whom he clearly dislikes due to his bumbling behaviour), but Mace does not realise this and continues plaguing Tycho on the way to the docks, loudly singing.
At night, while following Trant, Arya overhears Meryn telling two Lannister soldiers how poorly he thinks of Mace and the Tyrells, going as far as calling them traitors
Hand of the King Kevan Lannister has invited Olenna to sit on the Small Council – which officially now consists of Kevan, Grand Maester Pycelle, and Mace – at least to deal with the situation of Margaery and Loras's imprisonment. Barging into a Council meeting, Cersei expresses irritation that Olenna was invited while she was not, to which Olenna counters that Cersei is not the queen anymore – Margaery is, being married to the current king. Kevan refuses to deal with Cersei and, conceding that he can't force her to leave thanks to the reanimated Gregor Clegane, has the Councilors, including Olenna, leave instead.
At another "meeting" of the Small Council, Olenna and Kevan are surprised when Cersei and Jaime actually come to parlay. Cersei explains that she and Olenna played right into the High Sparrow's hands by continuing to squabble instead of presenting a united front, and now the High Sparrow is planning to have Margaery do the Walk of atonement just like she did. The Lannister twins explain their plan: Olenna will have Tyrell troops liberate Margaery and Loras, and turn them over to the Crown's Justice (in this case, Kevan), for a civil trial. Kevan, in turn, will keep royal and Lannister troops away from the incident, in keeping with Tommen's orders not to antagonize the Faith. Olenna opines that it isn't a particularly good plan, but agrees that at this point, it's their only option, and if blood is spilt, better it be the Sparrows' and not theirs.
Olenna accompanies Mace and his his column of Tyrell troops to the Great Sept to watch the proceedings herself. She and Jaime exchange worried glances when the realize that the High Sparrow is up to something. She moves closer to Jaime and Mace when Tommen appears and announces the new alliance between the Crown and the Faith. When Mace asks her what just happened, Olenna gruffly replies that they've been beaten.
Following the alliance between the Iron Throne and the Faith Militant and the conversion of King Tommen Baratheon and Queen Margaery Tyrell, Olenna meets with Margaery, pressuring her to turn away and stand against the Faith Militant. She reminds Margaery that they have her brother Loras, though in the presence of Septa Unella, Margaery says he must atone for his sins. Margaery gives Olenna a folded not. When Margaery and Septa Unella leave, Olenna unfolds the note, which contains a drawing of a rose; the House Tyrell sigil. She smiles at the strong implication Margaery is tricking the sparrows.
She later receives a visit by Cersei Lannister, who urges her to fight against the Faith Militant. Olenna says that she is leaving for Highgarden. Trying to convince Olenna, Cersei tells her they have a common enemy, and that they should unite and defeat him. Olenna, however, reminds Cersei of the smug look she gave her when Loras and Margaery were being dragged away by the Faith Militant. Olenna tells Cersei the truth of the matter; Cersei has no friends and is surrounded by enemies and has absolutely no support. She then adds that her only joy comes from the fact that Cersei has truly lost.
After the deaths of her son and grandchildren, Olenna travels to Dorne to meet with Ellaria Sand. After silencing the Sand Snakes, Olenna tells Ellaria that she no longer cares about survival. Ellaria alters her offer to say vengeance and justice, gesturing towards an approaching person. Olenna turns to see Varys, who says "Fire and Blood", the words of House Targaryen.
Matriarch of House Tyrell, Lady Olenna is not shy about sharing her opinions. She fought tirelessly to free her grandchildren from prison, even after discovering the High Sparrow was incorruptible. After Cersei's act of war killed Margaery and Loras, Olenna traveled to Dorne, where she entered into an alliance with Ellaria Sand in support of the Targaryen cause.