I. The value of town-planning to Roman civilization was twofold. It increased the comfort of the common man; it made the towns stronger and more coherent units to resist the barbarian invasions. When, after 250 years of conflict, the barbarians triumphed, its work was done. In the next age of ceaseless orderless warfare it was less fit, with its straight broad streets, for defence and for fighting than the chaos of narrow tortuous lanes out of which it had grown and to which it now returned. The cases are few in which survivals of Roman streets have conditioned the external form of mediaeval or modern towns. We in England tend perhaps to overrate the likelihood of such survivals. Our classical education has, until very lately, taught most of us more of ancient than of mediaeval history, and when our antiquaries find towns rectangular in outline and streets that cross in a Carfax, they give them a Roman origin. Such a tendency is wrong. Plentiful evidence shows that even in Italy and even in towns where men have dwelt without a break since Roman days, the Roman streets, and with them the Roman town-plans, have far oftener vanished than endured. Rome herself, the Eternal City, uses hardly one street to-day which was used in the Roman Empire. Some few Italian towns, described in detail above, have a better claim to be called 'eternal'; half a dozen in northern Italy retain their ancient streets in singular perfection. Yet even there cities like Padua and Mantua, Genoa and Pisa, have lost the signs of their older fashion. So, too, in the provinces. In the Danubian lands only one town can even be supposed to preserve a few of its Roman streets. In all the once great cities of that region, Sirmium and Siscia, Poetovio and Celeia and Emona, they have wholly gone; you may walk across the sites to-day and seek them in vain in modern street or hedgerow or lane. In Gaul there were many Roman municipalities in the south; there were many towns of lesser rank but equal wealth in the centre and west and north. But we owe our knowledge of their town-plans to an inscription from Orange and to some excavations at Autun and Trier. Cologne and Trier alone, or almost alone, keep Roman streets in modern use, and they are significant. Both became Roman towns in the first century; both held colonial rank; both have lived on continuously ever since and hardly changed their names. Yet both bear to-day the stamp of the Middle Ages, and the Roman streets which they use are small and nearly unrecognizable fragments.