For much of human history, fourteen years was considered an appropriate age to get married.
This is reflected in Shakespeare's work Romeo and Juliet, in which Juliet is at a “pretty age” (meaning an age to consider gett8ing married) as she approached her fourteenth birthday.
The Jewish tradition of Bar Mitzva reflects a cultural principle that held young men to be ready for the responsibilities of adulthood (including marriage) at thirteen.
Adulthood being held off to an older age than that is a relatively recent thing; reflecting, in my view, that society has become much more complex, and it takes longer to achieve the maturity and knowledge to function as an adult therein.