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Peaky Blinders star Cillian Murphy transforms to play ‘father’ of the atom bomb

Cillian Murphy
Cillian Murphy in Oppenheimer. (Image credit: Bobby Bank/GC Images)

We’ve become well used to Cillian Murphy in period costume after six seasons of hit drama Peaky Blinders, but for his latest role in Oppenheimer the Irish actor has undergone a substantial weight loss.

It’s been reported that the 46-year-old star lost a stone to play pioneering theoretical physicist J Robert Oppenheimer in the film by Tenet director Christopher Nolan, who worked with Cillian on The Dark Knight.

Judging by the photos from the set of the film, which is currently shooting on location in Princeton, New Jersey, Cillian did not have a lot of weight to lose, because he looks gaunt to the point of unwell despite his dapper grey suit and brown fedora. 

Cillian Murphy

Cillian Murphy on the the set of Oppenheimer in New Jersey. (Image credit: Bobby Bank/GC Images)

On the surface, the role of J Robert Oppenheimer is quite a departure from the charming, troubled crime lord Tommy Shelby. His work in the US government’s secretive Manhattan Project during the Second World War was responsible for creating the first nuclear weapons, a role which led to him becoming known as the ‘father of the atomic bomb’.

The atomic bomb was soon used on the Japanese cities of Hiroshima and Nagasaki but Oppenheimer was upset by the second bomb, considering it unnecessary and setting him at odds with the government. While he never actually admitted to regretting his part in building the bomb, Oppenheimer campaigned for nuclear peace in later years.

Oppenheimer is based on the Pulitzer Prize-winning book American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer by Kai Bird and the late Martin J. Sherwin and Cillian will be joined by an exceptional cast, including British actresses Emily Blunt and Florence Pugh, plus Robert Downey Jr., Matt Damon, Rami Malek, Benny Safdie and Josh Hartnett.

Oppenheimer is scheduled for release in summer 2023. Peaky Blinders season 6 came to a thrilling conclusion in April.

Patrick McLennan is a London-based journalist and documentary maker who has worked as a writer, sub-editor, digital editor and TV producer in the UK and New Zealand. His CV includes spells as a news producer at the BBC and TVNZ, as well as web editor for Time Inc UK. He has produced TV news and entertainment features on personalities as diverse as Nick Cave, Tom Hardy, Clive James, Jodie Marsh and Kevin Bacon and he co-produced and directed The Ponds, which has screened in UK cinemas, BBC Four and is currently available on Netflix. 


An entertainment writer with a diverse taste in TV and film, he lists Seinfeld, The Sopranos, The Chase, The Thick of It and Detectorists among his favourite shows, but steers well clear of most sci-fi.