24 August 410: the date it all went wrong for Rome?
Tuesday marks the 1,600th anniversary of one of the turning points of European history - the first sack of Imperial Rome by an army of Visigoths, northern European barbarian tribesmen, led by a general called Alaric.
It was the first time in 800 years that Rome had been successfully invaded. The event had reverberations around the Mediterranean.
Jerome, an early Christian Church Father, in a letter to a friend from Bethlehem - where he happened to be living - wrote that he burst into tears upon hearing the news.
"My voice sticks in my throat, and, as I dictate, sobs choke me. The city which had taken the whole world was itself taken," he said.
Although Alaric was a Christian ransacking a Christian city, there was an ominous feeling that the world structure built by pagan Rome was disintegrating.
The Roman Empire survived for a few more decades, and later other armies sacked the city again, but this was the date which marked the beginning of the end of Rome's grandeur.
Centuries later, the city which had at the height of its power boasted a population of more than a million people, was reduced to a lawless, ruined village of no more than 30,000 residents.
Marching in unopposed
Pagans claimed that Christians had destroyed the greatest human achievement ever contrived.
And Christians themselves, who had boasted that they had saved whatever was good in ancient civilisation, lifting it to new heights, suffered a crisis of confidence.
Although the now-Christian Roman Empire was divided between an Emperor of the West, ruling with his court from the city of Ravenna in Northern Italy and a rival Emperor of the East, ruling from Constantinople, there was a feeling that there had been a breakdown at the centre of things, in fabled Rome.
Historians and archaeologists from Germany, Switzerland, Britain and the United States specialising in the decline and fall of the Roman Empire have decided to meet in Rome in October and November to pool their latest research about this first Sack of Rome.
One of the organisers of the conference is Philipp Von Rummel of the German Archaeological Centre in Rome.
I asked him if 24 August 410 might be considered the 9/11 of the ancient world.
"Probably even more so," he replied. "I don't know if people will still be talking about 9/11 in 2,000 years time, but the events of that August day still influence our contemporary view of history."
Who exactly were the Visigoths, the barbarians from the North who marched unopposed into Rome?
Mr Von Rummel says the latest research reveals a very different picture from that held as recently as 50 years ago.
"Today we know the group consisted of different people, it was mainly an army with a successful leader. People joined this group inside the Roman Empire. They sacked a lot of towns but they acted in different ways, they also were a sometime partner of the Romans," he said.
"The moment the Roman emperor did not pay any more they changed sides and sacked the town just to tell the emperor: 'You should pay us'."
Looting and pillaging
I went to look for evidence at the northern walls of Rome, still almost intact for long stretches after nearly two millennia.
There is a gap marking the site of the former Salarian Gate just across the road from a modern department store. Alaric's army took the Via Salaria - the so-called salt road - linking the city to the Adriatic Sea.
When the city gates were opened by slaves, Alaric's ragtag army rushed inside to loot and pillage. The sack lasted for only three days, after which Alaric withdrew and marched south to set sail for North Africa, an important and wealthy Roman province.
But Alaric never made it. His ships were destroyed in a storm and he died shortly afterwards.
Many Romans fled to North Africa for safety. There, in Hippo, an important coastal town in what is now Algeria, the local bishop, Saint Augustine, was inspired to write one of his seminal works, The City of God.
Augustine, just like Jerome, felt he had lost his bearings with news of the collapse of Rome. Once Rome had gone, what sense was to be made of the world?