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.