There are two types of corruption (I believe):
1)If you reach a certain amount of money (ie 50000 100000 etc) something gets triggered that can get bad traits for your family members.
2)Also, corruption is very common in moneymaking cities. You'll lose quite some money in the end, but it's almost inevitable. You can only lower it by moving your capital or putting a good governor in the city.
Outoi sunechthein,
Alla sunphilein ephun
- Antigonč
Not to hate,
But to Love I was born