Replacing a higher age leader with a lower one

[lFlowerl]

Hi, just into this game for couples of weeks.
Rule question. I am curious about whether it is allowed to replace a higher age leader with a lower one?
For example, replace age-III Gandhi with some age-II leader.
Cause I just had a 2 player game where opponent played Gandhi, so I put all my millitary units into colony and found out that he had Robespierre in hand.
He didn't end up playing it and I won, but I'm scared of the possibility that he can replace the Gandhi and do aggresion on me.
So is it allowed in rules to replace a higher age leader?

[Remkar]

Hi, just into this game for couples of weeks.
Rule question. I am curious about whether it is allowed to replace a higher age leader with a lower one?
For example, replace age-III Gandhi with some age-II leader.
Cause I just had a 2 player game where opponent played Gandhi, so I put all my millitary units into colony and found out that he had Robespierre in hand.
He didn't end up playing it and I won, but I'm scared of the possibility that he can replace the Gandhi and do aggresion on me.
So is it allowed in rules to replace a higher age leader?

Yes, you can replace a higher age leader with a lower age leader.