We may take another example from a northern city, Trier on the Mosel, in north-eastern Gaul (Augusta Treverorum). It was in its later days a large city, perhaps the largest Roman city in western Europe. When its walls were built and its famous north gate, the Porta Nigra, was erected, probably towards the end of the third century, they included a space of 704 acres, twenty-five times as much as the original Timgad, though, it must be added, this area may not have been wholly covered with houses. But it was then an old city. Its earliest remains date from the earliest days of the Roman Empire (A.D. 2), when it was founded, like Autun, on a spot which had (as it seems) never been inhabited before.[105] Of this first beginning we possess vestiges which concern us here. Eight or nine years ago, when the modern town was provided with drainage, the engineers of the work and the Trier archaeologists, headed by the late Dr. Graven, combined to note the points where the drainage trenches cut through pieces of Roman roadway.[106] [105] Ademeit, _Siedelungsgeographie des Moselgebiets_, pp. 367, 431. [106] H. Gräven, _Stadtplan des römischen Triers_ in _Die Denkmalpflege_, 14 Dec. 1904 (1:10,000); the plan has been often copied, as by Cramer, _Das röm. Trier_ (Gütersloh, 1911), and Von Behr, _Trierer Jahresberichte_, i. 1908. Compare Barthel, _Bonner Jahrbücher_, cxx. 106. Trier at some time or other became a 'colonia'. When this occurred, is hotly disputed; the evidence seems to me to suggest that it was founded without colonial status and became a 'colonia latina' in the course of the first century (see Domaszewski, _Abhandlungen_, p. 153). I have therefore inserted Trier in this chapter with Autun and not in Chapter VIII with Orange and Timgad.