Heartsbane is the ancestral Valyrian steel sword of House Tarly. It is a two-handed greatsword. For the last five centuries, the sword has been a family heirloom passed down from one Lord of Horn Hill to the next.
A Clash of Kings
A Storm of Swords
Samwell has a dream featuring Heartsbane.
A Feast for Crows
When Lord Dunstan Drumm mentions Randyll and his famous sword will be part of the Reach army who will battle the Ironborn, Victarion Greyjoy gets excited at the idea of stealing the sword from Randyll, like Dunstan's ancestor did with Red Rain.