In my childhood the legal age for marrying and for marrying without parental consent was 16 in Scotland, and a girl who was pregnant at 15 could apply for and receive permission to marry before her 16th birthday.
In England you had to be 21 to marry without parental consent, and I have no idea, at what age you could legally marry with parental consent, but I think it was higher than 16, hence the popularity for eloping to Scotland to marry, which had a brief resurgence in the 1960s.
In Denmark, until the mid-1970s a girl could marry with parental consent at 18, whereas a young man had to be 21 whether his parents approved of his engagement or not.
Both could receive official permission to marry at slightly younger ages if a child was on the way.
Practically every country in Europe had different ages for marriage, consent to sex and for when you could be tried as an adult if you committed a legal offence.
Nowadays, most if not all, countries in Europe regard 18 as the age of legal majority, but I suspect whether you can or cannot legally marry below that age, or the age of consent is a legal minefield.
Those of you who have grandsons would be well advised to point out to them that the age of consent differs widely within Europe and between American states to this day, so if they go travelling they should not just assume that if it is legal at 15 at home, it is also legal elsewhere. Male homosexuality still has a later age of consent in certain countries than heterosexual relations do.
In Denmark it is now a crime to have sex with a person who has not clearly stated verbally that she is willing. How one proves this, beats me, as there are unlikely to have been witnesses present when the parties decided to go to bed together.