Manchester’s police are on alert for fan-piloted drones. Sniffer-dogs will be deployed to stop flares and fireworks being smuggled into the stands and over 400 officers will stand guard to keep the Blues and Reds apart.

The Manchester Derby has never had a reputation for the kind of serious violence that regularly blights notorious big-city rivalries such as Rangers and Celtic, Lazio and Roma or Istanbul’s Besiktas and Galatasaray.

And it is unlikely ever to claim the title of the World’s Most Violent Football Derby. That almost certainly belongs to the meetings between Cairo’s deadly rivals, Al Ahly and Zamalek. When they play, a nation of 82 million people are divided in bitter enmity, Whites against Reds. The Egyptian football authorities have to fly in foreign match officials, entire army regiments are mobilised and violent riots regularly claim the lives of supporters.

Sporting rivalry between regions can be fierce, north against south or city slickers versus country cousins. In Gaelic football we have Cork vs Kerry, Armagh vs Tyrone or Dublin vs Everybody.

But when the clash is between two halves of the same city, people who share the same streets for most of the year, it can get really personal.

Forget the platitudes about “banter” and “Monday morning bragging rights”. When Big City rivals clash, it’s a visceral, tribal thing, often wrapped up in politics, religion or class.

There’s something about the enemy within, the sense that your neighbours, workmates, the people you see in the local, are heretics, a foreign tribe that lives amongst us.

And it’s not a particularly modern phenomenon. When Besiktas and Galatasaray fans fight on the streets of Istanbul, or the left and right divided Ultras of Lazio and Roma pelt each other with stones and bottles, they are merely carrying on a tradition that goes back to the age when both cities were at the centre of empires.

When Istanbul was Constantinople, the worst communal violence ever to hit the capital of the Byzantine empire were the so-called Nika Riots, which saw the supporters of two rival chariot racing teams almost burn the capital to the ground.

Both the Romans and the Byzantines had a long tradition of factions within the city supporting different chariot or gladiatorial teams. In Constantinople around AD 530, only two Chariot teams counted, the Reds and the Greens.

Major races could attract up to 150,000 fans to the vast Hippodrome stadium. And Derby Day rioting between factions regularly resulted in hundreds of deaths.

In AD 532, a routine riot between the Blues and the Greens escalated into a week-long orgy of violence and destruction that swept through the city. Emperor Justinian (a Blues supporter) was almost killed. Half the city was burnt out and when Justinian finally sent the troops in to the Hippodrome, about 30,000 fans were slaughtered.

The Nika Riots were not just about chariot racing. The various factions were also divided along religious, political and class lines. Blue and Green were just the colours they used to mark their tribal identities.

As anybody who has been to a Glasgow derby can tell you, religion and tribal rivalry still plays a part. Most pubs in Glasgow city centre have “No Colours” signs on their doors throughout the year. They don’t want the sight of a blue or green scarf causing a trouble between drinkers. When the two teams play (not such a regular occurrence at the moment given Rangers’ recent financial meltdown and subsequent relegation) large parts of the city are virtually on a war footing.

At its worst, Rangers v Celtic is about ugly, vicious sectarianism. And going to one of those games can be bizarre experience if you are from Ireland and not particularly given to violent views on the Williamite Wars or whether the Bible alone is the true source of God’s salvation.

English football grounds may have become safer places since the dark days of the 1970s, thanks to better policing, the influx of TV money and the astronomical rise in ticket prices, which have helped make the game a more middle-class pastime.

However, the potential for trouble is always there. And in some countries, including Italy, the former Yugoslav states, Poland and Turkey, club rivalry can still spill over into serious violence.

That’s not to say that cities must always be divided between rival colours.

During the Egyptian revolution against the Mubarak regime, the country was stunned when TV news cameras showed gangs of hard-core Al Ahly and Zamalek supporters marching together in protest.

Fans from both clubs are fond of saying it was only when Mubarak and his cronies saw the Whites and the Reds, standing together in Tahir Square, that they realised the game really was up.

When it comes to rivalries, what makes us tick?

What is the psychology behind rivalry? What is it that drives these deeply-rooted competitions – and how does it have such a potent effect? Research has suggested many intriguing aspects to this:

• A group of researchers in the US found that individuals and groups that are "similar to one another... who have repeatedly competed against each other... and who have been evenly matched during prior contests" are most likely to see each other as rivals. When facing each other, they are potentially more likely to motivated to really push themselves, compared to when they are facing those who are not long-term rivals. In that sense, rivalry can be a powerful motivational tool for both teams and individuals.
• However, the same research also suggests possible downsides to this level of competition. Rivals could engage in irrational or unethical behaviour, be unwilling to cooperate with each other or even sacrifice their own gains in order to limit those of their rival.
• The enthusiasm fans show when facing rivals can also feed into performance. It has been suggested that the passion and commitment of fans can positively impact a team's performance, and nothing brings out fans' passion quite like a local rivalry.

Some food for thought next time you are watching a local derby...