Uploading a Mod to Steam Workshop
Now you have made a mod, uploading it to Steam Workshop is a simple process.
Make sure your mod pack has a unique name so it will not conflict with other mods, and that it is located in your Rome II data folder along with an image for your mod. This should be a 256x256 png image with the same name as your mod pack. If you do not have this image you will get an error message on trying to upload.
Run the game and go to the Mod Manager. You should see a new entry there with the name of your mod pack along with an upload button. Clicking it will prompt you to select which tag you want for your mod. The tags are:
Graphical
UI
Overhaul
Battle
Campaign
Units
Compliation
Maps
Pick the one that is most relevant.
Once your mod has been uploaded you will be taken to the Steam Workshop page for it where you can edit its title, description and upload additional images/videos to help promote it. Save the details and it will be available for everyone who owns Rome II to subscribe to and use themselves in their games.