A Feast for Crows (mentioned)|
A Dance with Dragons (appendix)
A Feast for Crows
In Braavos, men are challenged to a duel by bravos if they do not say that the Nightingale is the most beautiful woman in the world when asked. Cat of the Canals claims to Samwell Tarly that her father was killed when he said her mother was more beautiful than the Nightingale.