Leave Dragonstone and visit the Fishing Village just outside the town.Enter the tavern and speak with Ser Gilbert Farring.Speak in Bryen Farring in the castle of Dragonstone.Since it's one of the only two-handed blades that can be used on a horse, it makes a good substitute for a lance if you have more points in two-handers than polearms. It makes a good weapon for duels against armored opponents but if you get ganged up on it's better to switch to another weapon. It is essentially a large rapier, and is a good piercing weapon but it's not as great for slashing. The Braavosi Great Sword is a unique two-handed blade, won as a quest reward from the quest 'Seed of the Dragons'.
