If the huge amount of factions already available in Total War: Rome II isn't enough for you and you're feeling creatively minded, you can now download the Rome II Assembly Kit, a suite of newly released mod-tools for the latest Total War title.
The Assembly Kit contains a series of tools to help modders edit ROME II's database and variants, and process data such as textures, models, animations and campaign-game start positions. A suite of exporters also enables users to then edit unit models and animations using third party software.
For more details on how to download the new tools, and for hints and tips on how to use them, follow this link.