|House Goodbrother of Hammerhorn|
|Coat of arms||Gules, a warhorn sable banded or.|
|Lord||Lord Gorold Goodbrother|
House Goodbrother of Downdelving|
House Goodbrother of Crow Spike Keep
House Goodbrother of Corpse Lake
|Founder||Grey King's eldest brother|
|Founded||Age of Heroes|
House Goodbrother of Hammerhorn is a noble house from the Iron Islands. They are one of the most powerful houses from Great Wyk, the largest of the islands, and are one of House Greyjoy's primary bannermen. Their keep of Hammerhorn is inland, in the Hardstone Hills, their wealth not coming from the Sunset Sea but from their mines.
House Goodbrother has at least three cadet branches on Great Wyk, the Goodbrothers of Corpse Lake, the Goodbrothers of Crow Spike Keep, and the Goodbrothers of Downdelving. Other branches include the Goodbrothers of Shatterstone on Old Wyk and the Goodbrothers of Orkmont.
When the kingsmoot was used to choose the High King of the Iron Islands, only House Greyiron had more kings chosen than the Goodbrothers. Urrathon IV Goodbrother was a high king known as "Badbrother" during the Age of Heroes.
After the death of Lord Dalton Greyjoy at Faircastle, Gunthor Goodbrother slew Alester Wynch in a feud over Lysa Farman. Ser Leo Costayne, the lord admiral of the Reach, led an invasion of the Iron Islands on behalf of Lady Johanna Lannister in 134 AC, but Leo was slain by Arthur Goodbrother during the fighting. Lord Goodbrother was put to the sword by westermen by war's end.
A Clash of Kings
When Theon Greyjoy arrives at Pyke he sees a great number of longships, including some bearing Lord Gorold Goodbrother's banded black warhorn. The main strength of Lord Goodbrother amounts to near forty longships at Lordsport. Theon thinks the Goodbrother men are notorious at Pyke for their striped goat hair sashes. Asha Greyjoy came to Pyke from Great Wyk with Lord Goodbrother, and spent the night at Lordsport's inn until she met Theon. When entering the great hall with his father's captains Theon sees some Goodbrothers of Great Wyk.
A Feast for Crows
Lord Gorold, with the Sparr and his son Steffarion, brought to Aeron Damphair the tidings of King Balon's death. Aeron has a certain disdain for the Goodbrothers, because their keep of Hammerhorn in the Hardstone Hills is far from the sea and their wealth come from the mines beneath the earth. Aeron takes Gormond's horse after receiving the news of Balon's death, even though Steffarion offers his instead.
Some Goodbrothers from Great Wyk gather at the kingsmoot on Old Wyk to wish Victarion Greyjoy well. Two of Gorold's sons get into a fight at the kingsmoot. Although Gorold is initially a supporter of Victarion, after Euron Greyjoy's speech he is spotted by Aeron chanting Euron's name.
House Goodbrother of Hammerhorn at the end of the third century
The known Goodbrothers of Hammerhorn during the timespan of the events described in A Song of Ice and Fire are:
- Lord Gorold Goodbrother: Lord of Hammerhorn.
- Gysella Goodbrother, his daughter
- Gwin Goodbrother, his daughter
- Ten more daughters.
- Greydon Goodbrother, his eldest son and heir. First of the Goodbrother triplets.
- Gormond Goodbrother, his second son and second of the Goodbrother triplets.
- Gran Goodbrother, his third son and third of the Goodbrother triplets.
- Urrathon IV Goodbrother, known as "Badbrother", a High King of the Iron Islands during the Age of Heroes.
- Gunthor Goodbrother, commander of the Greyjoy garrison at Faircastle in 133 AC.
- Lord Goodbrother of Great Wyk, put to the sword by westermen during Lady Johanna Lannister's invasion of the Iron Islands in 134 AC.
- Arthur Goodbrother, who slew Ser Leo Costayne in 134 AC.
- The World of Ice & Fire, The Iron Islands: Driftwood Crowns.
- A Game of Thrones, Appendix.
- A Feast for Crows, Chapter 1, The Prophet.
- A Clash of Kings, Chapter 11, Theon I.
- The Citadel. Heraldry: Houses in the Iron Islands
- The World of Ice & Fire, The Iron Kings.
- The World of Ice & Fire, The Iron Islands: The Greyjoys of Pyke.
- A Dance with Dragons, Chapter 26, The Wayward Bride.
- Fire & Blood, The Lysene Spring and the End of Regency.
- A Clash of Kings, Chapter 24, Theon II.
- A Feast for Crows, Chapter 18, The Iron Captain.
- A Feast for Crows, Chapter 19, The Drowned Man.
- A Feast for Crows, Chapter 29, The Reaver.