Rise of Mankind: A New Dawn is an expansion of the existing, and incredibly popular Civilization 4: Beyond the Sword Mod, Rise of Mankind, by Zappara. Rise of Mankind attempts to simulate history, but was not intended to be a perfect historical simulator, like Rhye's and Fall of Civilization is; instead it follows mostly historical lines, but allows for those "What-If" scenarios to occur. Rise of Mankind serves as an expansion from Beyond the Sword, adding a huge new technology tree, putting great importance on buildings and creating infrastructure, along with incorporating other successful mods, like Revolutions, Influence Driven War, Next War, and much more. The Goal of Rise of Mankind: A New Dawn is to provide the player with the same enthralling experience that Rise of Mankind gave, without forcing any unwanted features or constraints onto them. This goal has been the central piece in all of A New Dawn development. This means that every single feature is completely optional.
Lots of new features, documentation in the civilopedia. Enjoy!