Idrien Tarsin is Headmistress of the School of Cairhien.
She is stocky with a blunt face. Her black hair is graying.
She makes a massive crossbow in the battle against the Shaido which was attached to Cairhien's wall. Rand al'Thor was so impressed that he puts her in charge of the new school of inventions. She runs the school with a tight rein and has a known dislike for Herid Fel.
She finds the remains of Fel and passes out. When she comes round she runs to Rand and breaks down when she attempts to tell him what happened.
She shows Rand through the school, when he arrives with Min Farshaw to pick up some of Fel's books.