These kinds of state marriages were common even in the 18th century. IIRC then the last French kings wife Marie-Antoinette were 14 when she and Louis married. Also, usually there was a deal between the father and his daughters soon to be husband that they can't do you-know-what until she is in certain age. These were more states-marriages than anything else.
I have also read that this was not that common in the lower classes though and commoners usually didn't arrange these kinds of marriages.