A Song of Sea and Storm
House Sioccrass has always been the richest House in the empire. In fact, they essentially bank-rolled the entire empire when it was founded, lending massive sums of money to the Ords and every House that settled Ur-Vaalbara.
Before the rebellion, every House owed money to the Sioccrass. The Sioccrass joined with the Ords against the rebel Houses because the Sioccrass and the Ords have always been closely allied, often inter-marrying. When the rebel Houses broke the loyalists, they demanded that all their debts to the Sioccrass be erased, which lessened the Sioccrass’ fortunes. For a time.
The Sioccrass diversified, expanding their mercantile efforts to include trade with Essos, Westeros, and Aine. Quickly returning them to their position as the richest House in Ur-Vaalbara.
The Sioccrass, before the rebellion, also enjoyed several unique legal protections in exchange for funding the beginnings of the empire. Polygamy and slavery were legal in Sioccrass territories, though they could not sell slaves to other Houses in Ur-Vaalbara. These “special” privileges the Sioccrass enjoyed became one of the rallying cries of the rebellion.
After the rebel Houses overthrew the Ords, these practices were outlawed in Sioccrass territory, though their current King prefers to pretend the polygamy ban was never enacted.
House Sioccrass does not have its own standing army, it relies on mercenaries to enforce its war policy.