I was watching a fictional series situated in XV century France, where a girl (princess) aged 8 married a +18 years old man (prince), through the Catholic Church. I wonder whether that was actually possible. 

It seems in the "Middle Ages" (unclear what exactly which years this is to represent) the minimum "legal" (Church?) age for marriage was 12 for girls and 14 for boys (e.g. see [here](http://www.themiddleages.net/life/marriage.html) and [here](https://www.medievaltimes.com/teachers-students/materials/medieval-era/marriage.html)). Currently, according to Canon Law, it's 14 and 16 respectively (e.g. see [here](https://christianity.stackexchange.com/questions/12342/is-there-any-connection-between-minimum-age-for-marriage-in-catholic-church-and)).

I've been searching for the evolution of this regulation, but haven't found much more than the above. A [Wikipedia](https://en.wikipedia.org/wiki/Marriage_in_the_Catholic_Church#History_of_marriage_in_the_Catholic_Church) article about the history of marriage in the Catholic Church has no further information. Anyone know more about this?