Petyr Baelish
Olenna is first mentioned in "A Game of Thrones" (1996) and appears in "A Storm of Swords" (2000) and "A Feast for Crows" (2005). She is the matriarch of the powerful House Tyrell, the largest and second wealthiest of the eight Great Houses of Westeros. Olenna is characterized by her cunning, ambition, and sharp wit (the latter of which being the foundation for her title, the Queen of Thorns, alongside the Tyrell sigil of a rose). Although her family is allied with the Lannisters in King's Landing, she often finds her own machinations at odds with theirs, especially those of Tywin Lannister. She, along with Petyr Baelish, is responsible for the death of King Joffrey Baratheon during his wedding to her granddaughter and protégé, Margaery.