Source: Guide to the River Kingdoms, pg(s). 42
Ultrar Duneshifter was an ally of Morgan the White, and he was one of the many pirates to sign up to Morgan's Pirate Pact and relocate to what is now termed the Protectorate of the Black Marquis, in the River Kingdoms.
He took exception to the murder of Morgan in 4702 AR by the pirate who came to be known as the Crimson Marquis. He imprisoned the Crimson Marquis, and briefly ruled the Protectorate himself, taking the title of Rogue Marquis. However, he was unable to maintain his grip on power, and the Protectorate descended into chaos.