To say it's unusual for a 16-year-old game to get a new expansion is more than a bit of an understatement. And to be fair, that's not precisely what's happening with The African Kingdoms, the Age of Empires 2 expansion that was announced (but not named) in April: It is in fact an expansion to the HD remake that hit Steam in 2013. To-may-to, to-mah-to, I suppose. The important part is that it'll be out in a couple of days.
The African Kingdoms features four new campaigns—the Malians, Berbers, Ethiopians, and Portuguese—all of which are fully voice-acted. Naval combat has been rebalanced and now features two new units, the Fire Galley and Demolition Raft, as well as a unique new naval unit for one of the four kingdoms. (Which one of them remains a secret because reasons.) A new Sudden Death mode that appears to be a "fight until you die" type of experience has also been added.
Developer Forgotten Empires said in a separate blog post in October that The African Kingdoms will bring the same balance updates, generic technologies, and units to Age of Empires 2 HD as The Forgotten, the fan-made mod that became an official expansion in 2013, and vice versa: Owners of The Forgotten will get the African Kingdom units and balance changes, even if they don't own the new expansion.
Age of Empires 2 HD: The African Kingdoms will be out on November 5.