Most of the early popes had wives and families of their own.
Documentation?
Well, Peter had a wife... at least he had a mother-in-law.
It’s an archaic rule, based on some mumbo jumbo about monks, has kept many good men out of the priesthood and attracted many homosexual men to it.
After all, no one will ask why you don’t have a wife and kiddies if you’re a Catholic priest.