|Title|| Lord Reaper of Pyke|
Lord of the Iron Islands
|Book(s)|| The Sworn Sword (mentioned)|
The Mystery Knight (mentioned)
A Feast for Crows (mentioned)
A Dance with Dragons (mentioned)
Lord Dagon Greyjoy was Lord of Pyke and the Iron Islands during the reign of King Aerys I Targaryen. He last sat in the Seastone Chair "almost a hundred years" before the events of A Song of Ice and Fire.
The Sworn Sword
Around 211 AC, Lord Dagon and his ironborn raided along the Sunset Sea and the western coast of Westeros. They raided as far south as the Arbor, attacking and burning Little Dosk and carrying off half the wealth of Fair Isle and a hundred women. 
The Mystery Knight
Lord Dagon sent ironborn north, where Lord Beron Stark was gathering swords to drive him off, and House Lannister was building ships to fight him on the seas. Due to the timeline of events Lord Tybolt Lannister was probably the Lord of House Lannister at that time.
A Dance with Dragons
Quotes about Dagon
|“||In Dagon's day a weak king sat the Iron Throne, his rheumy eyes fixed across the narrow sea where bastards and exiles plotted rebellion. So forth from Pyke Lord Dagon sailed, to make the Sunset Sea his own. He bearded the lion in his den and tied the direwolf's tail in knots, but even Dagon could not defeat the dragons.||”|