August 2nd is the anniversary of the Battle of Cannae, Hannibal's greatest victory against ancient Rome. It's one of a handful of ancient battles that still gets frequently mentioned outside military history books. The clash took place on the wide coastal plain near the modern town of Barletta (known for its symetrical Swabian Castle and the Colossus of Barletta) on Italy's eastern, Apulian coast. When we cycled into the area, it was easy to get the sense that an epic conflict had taken place here. Visible from the saddles of our bicycles and extending for miles in either direction, stood thousands of fleshy grape-vines, resolute in their rows, like well drilled soldiers waiting for battle. If you ride up to the hilltop of Cannae and visit the museum there, you can wander through the ruins of a medieval village to a column that marks a viewing point over the battlefield. If you can't take a trip right now, you'll see all that in episode 5 of On Hannibal's Trial when it airs on BBCFour and on BBC i-player on 16th August!

Here are some reasons why the Battle of Cannae is not forgotten...

Bloodiest Day of Battle Ever

The death toll from this horrific clash is often hailed as the bloodiest single day of battle ever. Polybius estimates that close to 70,000 Romans died and modern historians generally accept a figure approaching that. A quick check of internet discussion groups on this topic and you'll read that battles like Borodino and Panipat are mentioned as possible competitors with Cannae for this gruesome glory, but usually Cannae comes out on top.

The Pincer Movement is Born

Cannae is also remembered because Hannibal is credited with, if not inventing, at least being the first we know about in detail to successfully carry out a new military tactic: double envelopment or the pincer movement. Hannibal's use of this tactic at Cannae is still seen as a perfect example of how a smaller army can destroy a larger one. In short, Hannibal allowed his centre line to give, the Romans followed and then Hannibal crushed the Romans from the sides with his heavy infantry and from the rear with his cavalry. We try to recreate this in episode 5 of On Hannibal's Trail by running around the battlefield pretending to be the two contending armies. I'm not sure that we explain what happened very well, but we had fun doing it.

The Generals Still Love it

General Norman Schwarzkopf, Commander of the Coalition forces that invaded Iraq in 1991 said, "I learned many things from the Battle of Cannae which I applied to Desert Storm." Given that General Schwarzkopf had other advantages during operation Desert Storm, like massive technological and air superiority over the Iraqis, it would be hard to assess how much Hannibal helped him, but commanders including Napoleon and Rommel have all paid tribute to the Carthaginian's tactics at Cannae and tried to emulate him. Military Colleges still mention Hannibal in their training manuals and often those same instructors, like Robert L. O'Connell (The Ghosts of Cannae) and John Keegan (A History of Warfare), are writing some of the books we read about Hannibal and the Punic Wars.

Hannibal's Genius

Cannae is regarded by military historians as a sign of Hannibal's genius because he not only effectively invented a new tactic, but he perfectly carried it out. Perfectly because he totally destroyed the Roman armies opposing him. Scholars say this battle set new standards for speed of movement, manoeuvrability and flexibility of command. The Carthaginian probably had a degree of luck but there is little doubt that he had incredible control over his army's movements. Not only was Hannibal on campaign in a foreign land, fighting an army twice his size, just communicating simple orders to his mulit-ethnic force, let alone demanding Olympic standard manoeuvres, would have been very complicated. In that light, victory at Cannae was all the more amazing.  But so was Rome's recovery in the years that followed, perhaps the main reason we remember Cannae.

Has anyone visited the battlefield at Cannae? What did you think?

Does anyone know which author started the reference to Cannae as the bloodies single day of battle ever?

Has anyone attended a military college somewhere and heard Hannibal mentioned?

Tonight, On Hannibal's Trail, Episode 3, 'Crossing the Rhone', broadcasts at 830pm on BBCFour and the BBC i-player: