Slaves, Concubines and the Legitimacy of Children

[Renatus]

the children would be citizens, as long as the centurion's wife was a citizen.

Yes, the daughter of the centurion and his citizen wife would be a citizen. But if the daughter then married a non-citizen Briton, I think it's extremely unlikely that her children would have any claims to citizenship.

It is a long time since I looked into this but my recollection goes along these lines. A marriage between a citizen and a non-citizen would not be recognised in Roman law. The father, therefore, would have no rights with regard to the children and they would take their mother's status. So, the children of our centurion's citizen daughter married to a Briton would be Roman citizens. On the other hand, if his citizen son married a non-citizen British woman, their children would be non-citizens.