Cheat Mode:
Press ~ during game play to display the console window. Type one of the following case-sensitive codes to activate the corresponding cheat function. Note: Family member names, settlement names, and other proper names must be capitalized correctly.

Effect - Code:
Give city more population - add_population
Give any trait your faction can have to a specific general - give_trait
Anything in city's building queue built automatically - process_cq
Get indicated amount of gold - add_money
Toggles fog of war - toggle_fow
Press Auto Retaliate button to automatically wins; enter code at the battle scroll - auto_win

Create a Unit:
Use the console to enter the following

create_unit "settlement or character" "unit ID" "amount (1-5)" "experience (1-9)" "armor (1-3)" "weapon (1-3)"

Example:

creat_unit "London" Longbowmen 2 9 3 3

The above code will create 2 units of Longbowmen in London with 3 Gold Chevrons, Level 3 armor and Level 3 weapon.

Unlock All Factions:
Find your way to the Medieval II Total War\data\world\maps\campaign\imperial_campaign directory and youll see a file called descr_strat. Cut and Paste the unlockable section into the playable section. Now just save and close and youll have all your factions unlocked.

Ancillaries:
Use the following entries with the give_ancillary code. Note: Some of these can be accompanied with a "level number", usually ranging from 1 to 5, giving additional bonuses (or penalties).

academic_advisor
accomplice
adultress
architect
chastity_belt
diplomatic_escort
explosives
femme_fatale
fine_cosmetics
herald
mercenary_captain
secret_love
witch_hunter
zealous_disciple
amerigo_vespucci
marco_polo
martin_luther
jan_zizka
raphael
niels_ebbesen
arnold_von_winkelried
geoffrey_chaucer
john_wycliffe
bertrand_du_guesclin
aldus_manutius
michaelangelo
hair_from_mohammeds_beard
doctor
tutor
bard
catamite
apothecary
drillmaster
quartermaster
biographer
mentor
taticius
brilliant_inventor
foodtaster
librarian
magician
mathematician
poisoner
shieldbearer
bodyguard
monk
Traits