Sega announced a new expansion for Total War: Attila today titled The Empire of Sand Culture Pack. This paid expansion adds three playable factions: Aksum, Himyar, and the Tanukhids. From Matty on the Total War blog:
Hailing from the harsh deserts of Africa and the Middle East, these factions are part of the new Desert Kingdoms cultural group, they bring new campaign and horde gameplay mechanics, events, enhanced religion features, and add over fifty unique units to Total War: ATTILA.
The new expansion comes out on September 15th. Check out the trailer on YouTube.