Here are a load of cheats for this game. Hold down [ALT] and type
in one of the following codes:

Herculaneum:
764     Start lightning
826     Start volcanic eruption
293     Give money to the army
472     End the level

Rome 1:
442     Bring on evening
443     Bring on night
719     Buy a slave
608     Buy a female slave
426     Start the slave trade
682     End the level

Britain:
223     Fire
234     Bring on night
235     Bring on day
232     Rain
490     End the level

Rome 2:
114     Buy a slave
442     Bring on evening
443     Bring on night
551     Own extra female slave
362     End the level

Egypt:
809     End the level

Rome 3:
403     Bring on night
434     Buy a slave
624     End the level