At first, therefore, the burgesses were in reality the protectors, the non-burgesses were the protected; but in Rome as in all communities which freely admit settlement but do not throw open the rights of citizenship, it soon became a matter of increasing difficulty to harmonize this relation -de jure- with the actual state of things. The flourishing of commerce, the full equality of private rights guaranteed to all Latins by the Latin league (including even the acquisition of landed property), the greater frequency of manumissions as prosperity increased, necessarily occasioned even in peace a disproportionate increase of the number of --metoeci--. That number was further augmented by the greater part of the population of the neighbouring towns subdued by force of arms and incorporated with Rome; which, whether it removed to the city or remained in its old home now reduced to the rank of a village, ordinarily exchanged its native burgess-rights for those of a Roman --metoikos--. Moreover the burdens of war fell exclusively on the old burgesses and were constantly thinning the ranks of their patrician descendants, while the --metoeci-- shared in the results of victory without having to pay for it with their blood. Under such circumstances the only wonder is that the Roman patriciate did not disappear much more rapidly than it actually did. The fact of its still continuing for a prolonged period a numerous community can scarcely be accounted for by the bestowal of Roman burgess-rights on several distinguished foreign clans, which after emigrating from their homes or after the conquest of their cities received the Roman franchise--for such grants appear to have occurred but sparingly from the first, and to have become always the more rare as the franchise increased in value. A cause of greater influence, in all likelihood, was the introduction of the civil marriage, by which a child begotten of patrician parents living together as married persons, although without -confarreatio-, acquired full burgess-rights equally with the child of a -confarreatio- marriage. It is at least probable that the civil marriage, which already existed in Rome before the Twelve Tables but was certainly not an original institution, was introduced for the purpose of preventing the disappearance of the patriciate.(4) To this connection belong also the measures which were already in the earliest times adopted with a view to maintain a numerous posterity in the several households.(5)