Population decline in the Roman empire:
Natalist policies[edit]
The diffusion of Christianity in the Empire caused some social changes within the aristocratic families. In several wealthy families, daughters were obliged to take religious vows and never marry, so that the family wealth would not be dispersed in dowries. Majorian thought that this behaviour was harmful to the State, because it reduced the number of Roman children, and because it caused the girls to start illicit affairs. On October 26, 458, the Emperor addressed a law, the Novella Maioriani 6, to the Praetorian prefect of Italy, Caecina Decius Basilius.[41]
This law, titled De sanctimonialibus vel viduis et de successionibus earum ("Holy Maidens, Widows, and Their Succession"), imposed a minimum age of 40 for taking religious vows, considering that at this age the sexual drives of the initiated would be dormant. The law also granted women who had been forced to take religious vows, and were subsequently disinherited, the same rights on the legacy of parents as their brothers and sisters.[41]
In order to solve this same problem of the decline of the Roman population, in particular compared with the growth of the barbarians allocated within the imperial boundaries, Majorian addressed the problem of young women widowed and without children who never remarried because of the influence of the clergy, to whom they destined their goods in their will.[42] The young widows were prohibited from taking religious vows.[42]
By the same measure, departing in this from the policy of the Eastern Empire, Majorian insisted that a marriage without dowry and pre-wedding exchange of gifts (first from the bride's family to the groom, then in the opposite direction) was invalid; he simultaneously ended the practice of requesting pre-wedding gifts of a value considerably higher than the dowry.[43]
Maybe there was a different fertility in the Roman heartland versus the periphery. That is not very surprising because that is something we see today too.
Topic: Qur'anic studies today