The scions of the Old Blood are influential and consider themselves to be of superior breeding. In Volantis, only those who can trace their ancestry back to Valyria can be triarchs, and only those of the Old Blood are allowed to live within the Black Walls of eastern Volantis. Furthermore, only they can invite slaves, freedmen, or foreigners to pass beyond the Black Walls. Inside the Black Walls, Volantenes of the Old Blood still keep court in ancient palaces, attended by armies of slaves.
The Old Blood supports the tiger party, which is made up of old aristocracy and warriors. They tend to be imperialists and advocate the sword. However, some of the Old Blood belong to the "elephant" faction, made up of merchants and moneylenders who advocate trade, such as Vogarro.
Many of the Old Blood of Volantis still keep the old gods of Valyria.
According to semi-canon sources, the Old Blood descends not of dragonlords or other Valyrian nobles but of the lowborn footsoldiers that made up the only inhabitants of Volantis for the first hundred years of the city.
A Dance with Dragons
According to Qavo Nogarys, a customs officer of Selhorys, the actions of Daenerys Targaryen has smashed the slave trade which Volantis and Qarth relied on. This has made Daenerys enemies of the Old Blood behind the Black Wall and beyond. Qavo tells Tyrion Lannister,
Behind the Black Wall, lords of ancient blood sleep poorly, listening as their kitchen slaves sharpen their long knives. Slaves grow our food, clean our streets, teach our young. They guard our walls, row out galleys, fight our battles. And now they look east, they see this young queen shinning from afar, this breaker of chains. The Old Blood cannot suffer that.