What did Nero and Caligula have in common, besides being murderous megalomaniacs? Both were ardent Greens. In Constantinople some 500 years later, Justinian and his wife Theodora were passionate Blues.
The Blues and Greens were two of the factions in chariot racing, who were supported by the populace in huge numbers. Along with their less celebrated rivals, the Reds and Whites, they provoked violent passions and the occasional riot in a tradition stretching from the late republic until the Twelfth Century AD. This is an extraordinary tale of sporting rivalry.
I first became aware of the Blues and Greens when researching my first, dead-in-a-drawer novel set in 6th century Constantinople. In this era, the violence from the racing factions spilled onto the streets: there were riots and massacres that make our football hooligans seem like benevolent pixies.
Now I am back again, but five centuries earlier. How important were the Blues and Greens in the early Empire - how prevalent, and how destructive?
Rawson argues that is it possible that it was about this time that the four factions emerged; effectively four different stables which paid for the chariots, horses and charioteers, perhaps from the ever increasing prize-money.
Charior racing was hugely popular. Ovid, in his Weinstein-ish poetry about how to pick up women, makes it clear that men and women sat together - close packed in narrow rows. The Circus Maximus could hold - it is argued - a staggering 150,000 race fans. Imagine the noise as the Blues passed the meta (the turning post) in the final round, beating the Greens back to a sullen second. I am reminded of attending a baseball game in America. The distances involved meant there were no rival fans. For someone used to British football and rugby grounds the atmosphere was weirdly leaden. Supporting any sport becomes more interesting when you are vested - somehow, anyhow - in the competitors.
Augustus - who cannily never let his preferences be known - understood the power of the Circus. He renovated and expanded the Circus, and sat his family on a large collective bench so that they could be seen to be first among equal citizens. As Andrew Feldherr points out, he chose the cliffs overhanging the circus to build his palace; the architectural symbol of the new order.
There is some doubt as to whether all four factions had a long history before Augustus began to incorporate the myths and iconography of the Circus into the elaborate mythical buttressing of his
Tertullian, writing in the third century AD, says that there were originally only two factions - red and white. This is disputed by modern historians.
Alan Cameron, in his seminal book on this topic, Circus Factions, argues that Tertullian's version is just one tradition, and that all the later versions are ripe with mythology and wish-fulfillment. Cameron argues that the origins of the Blues and Greens go far back in to the Republic - exactly when, we do not know.
Blues and Green became the major colours quickly, dominating the sources. Cameron argues that the precise relationship between the Blues and Greens on the one hand, and Red and White on the other, remains a puzzle. One version of the significance of the colours holds that they represent the four seasons - but as Cameron points out, this notion is part of later mythologising by Roman antiquarians.
There have been various theories propounded as to whether the support for different factions was related to anything specific - class or religion, in particular. In late antiquity it has been surmised that one faction denoted one specific view of the nature of Christ.
Cameron argues that there is very little evidence of these distinctions. "The truth is that Blues hated Greens, not because they were lower class or heretics, but simply because they were Greens."
I can understand the temptation to ascribe social or religious leanings to one side or another; it seems absurd to hate for no more reason than the colour of a charioteer's tunic. But I have been to football derby matches - a number of them. I have seen little to match the vitriol and hatred between fans of Sheffield Wednesday and Sheffield United. Unlike the other great football rivalries there is little to divide the fans - Liverpool, Glasgow and Manchester have their religious splits; Barcelona its political ones.
But in Sheffield, an owl hates a blade just because he's a blade. Just as a Blue hates a Green just because.
Even as Rome descended into its late Antiquity malaise, chariot racing remained central to the City. In Decline and Fall, Gibbon says of 5th Century Romans that they "still considered the circus as their home, their temple and the seat of the republic."
In Constantinople, meanwhile, the factions became central to the Empire's politics. Who you supported came to matter politically; and the violent uprisings of the factions became a live political issue. Cameron makes strong arguments for the reasons why the rivalry between factions spiralled through the centuries to erupt in riots and murders in the 6th century: He points to the factionalisation of other areas of public spectacle, like the theatre.
But with a novelist's head, and not a historian's, it strikes me that there is another factor at play - all that history! Imagine the weight of it, stretching over an unimaginable 1500 years or so. And this the type of history that clings so tightly to a myth that the two are indistinguishable. The generations of forefathers who were Blue or Green. Who took their Blueness or Greenness from Rome and into the provinces. From Rome to that spit of land at the edge of Asia. Being Blue or Green stops needing a meaning when the weight of history and myth and family presses its colour violently upon your soul.