During gameplay press TAB to get the console then put in a code below

STEFANREHN Invincibility
DIMMUBORGIR All Buildings Available
UTOPIA Defeat Rebels
MANUNITED Get $5000
AIK Subtract $5000
SVENSK No Declaration of War from Enemy
BURP No Events
RICHARDNICE Get 1000 Victory Points
RICHARDBAD Subtract 1000 Victory Points
KILLSTIG Kills Hertig Stig
KILLVALDEMAR Kills Hertig Valdemar
KILLERIK Kills Hertig Erik
KILLBIRGER Kills Konung Birger
KILLMENVED Kills Menved
KILLHAAKON Finish the Game