Cheat mode:
Enter one of the following codes at the campaign map:

Code - Result:

.mefoundsomeau. - Supply Provinces with Gold
.mefoundsomeag. - Supply Provinces with Silver
.mefoundsomecu. - Supply Provinces with Copper
.viagra. - Supply Provinces with Iron
.matteosartori. - Reveal Map
.deadringer. - Add $1 Million Florins
.worksundays. - Fast Construction
.badgerbunny. - All Units/Buildings Available
.conan. - Play as Rebel Parties

Command-Line Cheats
Use command line: "medieval_TW.exe -ian" to start the game, then the following keys are available while playing:

Code - Result:

a - Autorun
g - God Mode
i - Artificial Intelligence
h - Artificial Intelligence
s - Scenic Tour
F5 - Scenic Tour
CTRL + I - Panels
CTRL + 0-9 - Change Faction