Anyhow, I was just wondering if this has been the custom in other royal houses as well. Given that monarchy evolved into an hereditary institution, legitimacy has been of utmost importance, when it comes to a child's status and rights. The opportunities for fraud are legion, so one would think that special pains would be taken to verify the identity of a royal child. As such, paternity is not the only complication to potentially compromise legitimacy ("Weren't the couple estranged, not having enjoyed relations in a long time? Did not the mother give birth alone in a far away land?").
Maternity, too, could be questioned in the days before modern molecular biology ("Did some peasant woman substitute her own child for the royal, to watch him grow up enjoying a life of privilege? Did some peasant woman substitute her child for the stillborn child of the queen, so as to spare her heartache and humiliation? Perhaps she took the dead child home and buried him in her own garden?").