Diminutive Hollywood megastar Tom Cruise leads a stellar cast in this watchable big screen dramatisation of the fifteenth and final plot to assassinate Adolf Hitler.

Cruise plays Colonel Claus von Stauffenberg who on July 20 1944 led a group of high-ranking conspirators in an attempt to kill the Führer.

Stauffenberg had been a loyal officer – losing his left eye, hand and a couple of fingers in an allied attack in North Africa two years earlier – but signed up to the German resistance after becoming disillusioned with Hitler’s inept leadership and mass slaughter of the Jews.

He came up with a brilliant but dangerous plot to assasinate the Führer and then overthrow the government using Hitler’s own emergency plan – Operation Valkyrie – which would be put in place if he was killed.

Stauffenberg volunteered to place the bomb himself in the Wolf’s Lair, Nazi HQ, in East Prussia – but, as history tells us, things didn’t quite go according to plan and once the failed plot was discovered the Führer ordered those involved to be rounded up and executed.

The casting of Tom Cruise as the hero is a mixed blessing. Cruise bears an uncanny resemblance to the real Stauffenberg and his steely interpretation of the determined Colonel is appropriate. But although capable, his performance is sadly unremarkable as it would be easy to see another actor in the role.

And Cruise’s decision to use his own all-American accent rather than attempting a German one – or even falling in line with the mostly British cast – was unwise and proves distracting.

A solid and largely impressive supporting cast including Kenneth Branagh, Bill Nighy, Tom Wilkinson and Terence Stamp play the key plotters.

However comedian Eddie Izzard’s unintentionally camp turn as General Erich Fellgiebel is bizarre and inappropriate. He comes across as a charicature rather than a real person. But David Bamber’s performance as the slightly doddery but menacingly deranged Führer is chillingly accurate.

Director Bryan Singer (Usual Suspects, X-Men, X2) offers little in the way of explanation of Stauffenberg and his co-conspirators’ motives and we find out almost nothing about their private lives. However, Singer does do well to build up the suspense both before Stauffenberg plants the bomb and afterwards despite the audience knowing they did not ultimately succeed.

Some of his camerawork such as the aerial shot tracking Stauffenberg’s car making its way through dense forest to the Wolf’s Lair is stunning. As is the high shot of a record playing Wagner’s Flight of the Valkyries cut with footage of Stauffenberg and his family hiding in their cellar during an air raid. The Colonel’s moment of revelation as he realises Operation Valkyrie is the answer to getting rid of the Nazis is brilliantly captured.

Valkyrie’s fascinating plot is undoubtedly its strength but the lack of characterisation stops it from being a classic.