Our theme today is the end of classical antiquity and and fall of the Western Roman empire.

The "Byzantine Empire" is an etymological invention of our modern historians. Those Byzantines called themselves Roman.

Gibbon said "The fall of Rome was like the crumbling of a fabric which gives way due to its own weight".

The idea that the Roman empire fell is modern. Is it event based, or is it process based? Is it due to internal weakness and failure of the system; or is it more to be laid at the door of those Barbarian hoards, who just got so numerous and so war-like and aggressive that they were able to overcome what was left of the great army and Roman machine.

The Roman empire was among other things a great economic engine. It was the centre of a global trading system that had its Western end in the Canary Islands, where we find Roman trade artifacts, and where we know that geometers like Ptolemy set their longitude, which was their zero line for there world maps; and we can then follow that trading system all the way East, to China, whose silk production was very important to Romans.

The great cities themselves go under.

Most of the cities of the Western empire are empty because they are not safe anymore. Regional security is now in the hands of a few strong military leaders, chiefs, warlords. You've got to attach yourself to them. In a small and humble kind of way, villas out in the countryside become the headquarters for these people: the nuclei for new towns, and the cities -- these great targets for wandering hoards -- since they are still filled with a jumble of sale-able stuff. They are not safe enough for settled life. The great trading systems, the system of cities itself, the polis of the Greeks, the urbs of the Romans: that was one of the pieces of bedrock under classical civilisation; and the idea of a human being, a citizen in the Greek and Roman world, is tied to a city. Take away the cities, and how can we have classical Greek and Roman civilisation any more? Well, in my view, we cannot.

Pollen studies show us that once the first farmers came into the Mediterranean 7, 8 thousand years ago, a process started of steady deforestation. But even though it started way back in the neolithic, it's a remarkable thing that the Romans and Greeks could still find masts for their ships, timbers for their temples from their own hills; and their own forests of a size and majestic quality that just don't exist today in the Mediterranean. Little by little, it was deforested. As it was deforested, the good soil was loosened from the slopes. Plato himself was aware of this. I believe I mentioned, as I talked about his vision of Atlantis, that Atlantis dated to a time when Athens still has rich soils and forests on its hills; and when the forests were cut down, which had happened in the time of grandfathers of his own generation, then the soil was loosened, it flowed down to the sea, and the result was a wasted skeleton of what had once been a healthy landscape. And the deforestation was pointed to by Plato, a contemporary of part of this process, as the culprit.

There are places where we find what appears to be up to 45 feet of mud, of sediments that come sweeping down off the mountains in historic times, and completely covering what might be lying there on the sea floor; and the mountains themselves are bare, right up until the water's edge. This has impact on the rainfall, the temperature, the number of crops you can raise, the extent of farms; the very basis for wealth in that world was eroded away.

So in this way, through all these processes: as we lose population, cities, economic system -- the environment itself failing to provide the rich resources that such a population needs; all of these things together are threads in Gibbon's fabric: that archaeologists can see one by one are being broken. Which thread is the one that ultimately causes the fabric to crumble beyond repair? It is something we could continue to debate; and I hope that as more effort is made, especially in the environmental area, to understand moment by moment, year by year, the transitions within that ancient world, that we will have a clearer idea of exactly what happened. But of one thing, I, have no doubt: that when we see those Roman buildings of the imperial age torn apart for what is called archaeologically, the "spolia": the spoils of those buildings that will now be put into the tombs, the buildings of the Ostragoths and the Visigoths; we have indeed witnessed the end of something that Wordsworth said once was great.

We started these lectures with Johann Joachim Winckelmann, the man who called art history into existence when he studied Greek and Roman statues. Winckelmann believed that we should study antiquity because the Greeks and Romans had created a perfect standard of art: something that we should try to emulate. He also believed that this perfection in art was shared by the entire culture in which the ancient Greeks lived. That richness, that complexity that we see in the art, is emblematic of what has been lost through the ages in our view of Greco-Roman civilisation.

I believe that all these assumptions and claims about the ancient world not only go too far, but they miss the point. By idealizing, one fails to see the humanity and complexity of this civilisation, and fails to learn all that these people had to offer.

A contrary tendency among some scholars and historians, is to emphasize the negative: the injustices, the horrors, the unrelenting warfare, and slavery. In this context, Winckelmann has some sound advice for archaeologists: "Don't be like schoolboys who simply look at the master to criticize and point out the faults. Until you have fully understood the good that a person has achieved, you are not ready to look at the bad". I think this approach is wise: we should assess the achievements of the Greeks and Romans; then consider aspects of those civilisations that were not so successful.

The point of any study, is to achieve what was written on the outside of the temple of the Delphic Oracle: "Know thyself.". We should all strive to know ourselves, and our world: but doing so while we are in the midst of that world can be difficult. We must look to worlds that most resemble ours, to see where other civilisations went wrong, and take steps to avoid the same mistakes. One element of the past that I hear challenged again and again from my students is warfare. Wasn't the Roman Empire basically a product of legions? Isn't the Parthenon the end result of the Athenian's navel conquests? Those assertions are true; but are we then forced to say that the whole Classical achievement would have been impossible without warfare? I don't think the evidence supports that conclusion. Some of the sites in Greece today do not date from the 5th century: the time of the Peloponnesian War between Athens and Sparta. Only after those wars were over did the economy blossom. From the 4th century on, we get the major building projects that still adorn Greek city sites today. In Rome, we learn that before there were legions, before there were wars, before the first conquest of a neighbouring city, the Romans had already resculpted their Seven Hills, and laid the foundations for their city. Their work wasn't the fruit of militarism, but a product of a confident citizen body directed by charismatic leaders.

For those of us who have come after, every day is a time for action. We must always struggle to perceive the dangers in our society, to choose the right path to correct the errors we have made, and to ensure that the world we live in will continue -- and will improve. Looking at the bridge at Alcantara, recalls some beautiful lines from the Iliad. Late in the book, King Nestor is coaching his son, Peisistratus, on how to win a chariot race. Peisistratus does not have the fastest horses, nor is he the most powerful contender in the race. But Nestor tells his son that he can win anyway, because achieving victory comes through wisdom and art: