The city gate, still guarding the main road into town, a great grim gate. Like the rest of the northern frontier, Trier was continuously threatened by Huns and Goths and Vandals and a dozen other warrior nations. Constantine the Great, the emperor himself would have walked down the same passage 1,600 years ago. These vaults and arches are the architecture of his time.

 

Once you’re through the gate, most Roman towns are almost the same, they were if you like, a sort of an abstract idea of a city, and they were stamped on every landscape from Yorkshire to Syria.

 

You can still sense their design in a thousand old world cities, and in the new world too. From Washington to San Francisco, planners still use parts of the same old patterns. All Roman towns had roads like this one, wide thoroughfares that took you from the country to the heart of the city. This one is at Palmyra, in the Syrian Desert. In Constantinople it was called, quite simply, the Main Road.

 

"Now what you gotta see, is that behind all these columns, there were little rows of shops running down the sides of the street, butchers, bakers, candle-maker(s), all sorts of people. In Constantinople, it would have the goods of the known world, Africa, China, the boutique, everything was for sale. Just imagine, the emperor, is coming in in triumph, he’s won a war, he’s coming through the gate. The shopkeepers have been told to dust down the street, flowers have been strewed all over the pavement, roses are raining down upon him, there are rugs and silks flattering in the breezes all around him, the whole town has been sucked out to come and see him.

 

Behind the course, behind the main street, full of town houses, servants, soldiers, all the people, there were taverns, brothels, everything in the city, in among stoas, started in among stoas with those huge buildings that Constantine had to build, before his city could really be called a Roman metropolis.