House Mallister of Seagard

Long before the Trident had a single king, the Mallisters were already fighting wars of their own: they took most of the Cape of Eagles from the ironborn in the days of Torgon Greyiron and settled the coast that would later bear their name.

When House Justman fell, no line was left holding the whole river crown. For a hundred years the Mallisters ruled as just one of several rival petty kings, until the Teague dynasty finally brought them all to heel.

Lord Petyr Mallister challenged the Storm Kings, the old House Durrandon, and got as far as crowning himself. It didn't last: defeat came quickly and put an end to that improvised reign.

When Aegon Targaryen landed to claim the whole of Westeros, the Mallisters didn't stand with Harren the Black: they joined the future king's cause and fought on his side in the war that ended the lordship of Harrenhal.

Of those broken kings something outlasted the centuries besides memory: they still call themselves Kings of the Trident, a title that rules over no one anymore but that no one has quite taken from them either.

At the Tourney of the Hand, amid the tangle of banners covering the field, someone can just make out the Mallisters' silver eagle flying alongside so many other riverlord banners.

The Mallisters had sworn fresh loyalty to the Iron Throne, but when the time came to ring Riverrun with a siege, their silver eagle was nowhere among the besieging camp's banners. No one explains why it was missing.