A long-standing family tradition states that only the Lord of Greywatch Keep, who is also the head of the family, may wield the sword. Greymere is a matter of great pride to House Harwood who believes that it represents their right to rule their lands and stands as a means of dispatching justice. If it were to be stolen the family would suffer immense disgrace which has meant that it remains in the vigilant possession of Lord Harwood at all times. The sword is used as the family patriarch's personal sword and as an executioner's blade when required. When not physically carried by Lord Seywyth for a number of reasons, Greymere is kept tightly secured and guarded in a hidden vault at Greywatch Keep.
The specially crafted longsword was gifted to Ser Branton Seywyth by King Daeron II Targaryen on the day of his ennoblement in 196 AL. Forged from particularly high quality Valyrian steel the ornate blade was given to Ser Branton by King Daeron II, also known as Daeron the Good, as a reward for defending the King's honour when he was insulted by a traitorous knight. Ser Branton challenged the offending knight to a trial by combat slaying him in a spectacular feat of swordsmanship which greatly impressed the King.
As a small child Ser Branton had watched from a hidden place as a large band of outlaws loyal to the Brotherhood Without Banners murdered his parents and burned down their farmstead. He named his sword in honour of the farmstead that had witnessed the dying moments of his beloved parents. The sword soon became a symbol of Ser Branton's prowess in battle and a tool to see justice brought to anyone who threatened his family. Greymere was passed down to Branton's eldest son Dunstan upon his death and will passed down to Dunstan's eldest son Gerrard in turn when he becomes head of the family.
Greymere was wielded by Dunstan in a matter of justice when he personally executed the traitorous knights Ser Edwin Carrant and Ser Kiran Wexley.