Press "~" while playing the game to bring up the console window. Now type "Barbarossa" in it to enable the cheat mode, and since then you can use one of the following codes to activate the corresponding function:
@God(0,1): God Mode
@God(0,2): God Mode + One Shot Kills
@Win(0): Win Battle
@ChangeWarFog (0) or (1): Remove Fog of War