Lord Gelmar Goodbrother is Lord of Hammerhorn and head of House Goodbrother. He is described as a giant of a man, barrel chested and tall, with a bushy mustache and grey streaks in his beard. He has two sons, Quellon Goodbrother and Ralf Goodbrother.
Lord Gelmar was a close friend with Lord Damron Greyjoy. He reaved alongside Damron up the northern coast sometime before the first era.
During the Second Greyjoy Rebellion, Gelmar accompanied Merryk Greyjoy to Greywater Watch. Merryk's death there and Gelmar's treatment of the two Lannister wards, Damon Lannister and Thaddius Lannister, after the rebellion put him in a position of discontent with Lady Alannys Greyjoy.
Lord Gelmar took part in the Ironborn's capture of the Shield Islands during the War of the False King.
He and his sons were later called back to Pyke due to a marriage offer from Alannys Greyjoy between her daughter and his son.
Quellon Goodbrother, son
Ralf Goodbrother, son
"He drinks more than a fish." - Thoughts of Gwin Greyjoy