Who is the Batman? Bruce Wayne? Sure, in a sense. That much was given away in the first episode of Batman – or ‘Bat Man’, as he was then called, in Detective Comics #27 of May 1939.

But Batman has been many things since then. He first appeared just prior to America’s entry into World War Two, and during those years of conflict, while the covers encouraged readers to do their bit through bonds and paper drives, his adventures of costumed criminals and gangsters in Gotham City had a reassuringly nostalgic feel. Many a frontline soldier must have found comfort in the fact that Batman stories still felt like something from childhood – an eternal 1930s of mobsters and clowns, an escape from everyday reality.

In his earliest years, the Dark Knight used a gun, and didn’t hesitate to kill – a memorable line of dialogue from those days has him declaring ‘Death... to Doctor Death!’ – but parents, politicians and educators objected, and by 1940 Batman had sworn never to use a firearm. He was also joined by a plucky little kid called Robin – Watson to his Sherlock – who gave kids a way of identifying with the stories. It was hard for a ten year-old to imagine himself as a grown-up crime-fighter, but he could sure imagine being the sidekick.

And that partnership took an unexpected route in the following decade. In the war years, Batman had been criticised for too much violence, and cleaned up his act; in the conservative 1950s, his stories were criticised for too much love. Love between the wrong people, at the wrong time, that is: it turned out that some young men were wishing they could be Robin, but more for the domestic idyll of living with Bruce than for the action adventures. Now, of course, those teenagers could call themselves gay, but in the mid-1950s they were dubbed inverts and perverts, and Robin was moved out of Batman’s bedroom, while a host of femmes fatales moved in. Funny, they never seemed to last long, whereas Robin’s still around.

The Camp Crusader can never be fully censored. In the 1960s, he rose up like a phoenix in the form of Adam West, intoning ridiculous lines (in a ridiculous costume) while taking himself absolutely seriously, and winning over a new generation of kids, teenagers, Pop Artists and gay audiences. That campy incarnation showed his gaudy colors once more in the 1990s, when Joel Schumacher took over the blockbuster movie franchise, turning Tim Burton’s more gothic baroque vision into a city-sized pantomime... on ice.

And that’s really where my new book, Hunting the Dark Knight, begins: with Batman Begins, Christopher Nolan’s 2005 reboot of the failing franchise. It picks up where my previous volume, Batman Unmasked, left off in the year 2000, and examines the various meanings of Batman in the 21st century.

What does the Bat-Symbol stand for, post-9/11? Why is Batman still popular, 73 years after his inception? Has he gone through so many changes over the years that he’s lost his core identity – meaning everything, but nothing? Is he a folk hero, belonging to the fans and the popular imagination, or a brand, a product owned by DC and Warner, used to sell movies, toys and fast food? (A Domino’s ‘Gotham City’ pizza, ‘cloaked in pepperoni’, was released with the last Nolan movie).

Nolan’s Batman Begins proved that Batman could be taken seriously again; his follow-up, The Dark Knight, went one better, and demonstrated that a superhero movie could provide a complex and powerful exploration of the ‘war on terror’. Nolan’s Joker was, simply, a terrorist: but the movie invited us to ask how far Batman could ethically go, in fighting fire with fire. Is the infringement of civil rights, rendition, harsh interrogation and surveillance justified, if it saves lives? Critics argued over the film’s political stance, but to his credit, Nolan offered no easy answers.

Now, in The Dark Knight Rises, Batman – returning to Gotham after an eight-year exile – faces a new threat. As the storm-clouds gather and crowds flood the streets, led by thuggish mastermind Bane, Bruce Wayne looks out of his depth for the first time since he put on the mask and costume.

It’s hard not to see Wayne, this time, as a privileged One-Percenter, a Wall Street banker, a capitalist businessman who’s built up his corporate empire and now sees it attacked by a mob of protesters. When that storm hits, Selina Kyle warns him, ‘you're all gonna wonder how you ever thought you could live so large and leave so little for the rest of us.’

Once again, Nolan makes his Dark Knight as topical and urgent as the day’s news headlines. Will Batman survive this challenge? Undoubtedly – because Batman is bigger than any movie, bigger than any brand. After seven decades, he’ll survive for as long as we remember him; for as long as kids pull a towel around their shoulders and order a little brother or sister to play the sidekick. But will Batman still be Bruce Wayne, by the end of this particular story? That’s less sure. Batman is a concept, more than one man alone, and Wayne may have to make the ultimate sacrifice, passing the mantle on to a younger crusader. Bruce Wayne is a billionaire, a businessman, a playboy, a guy used to playing big risks. But in Nolan’s final Batman movie, the stakes are higher than ever, and all bets are off.

In collaboration wih http://www.ibtauris.com/