The real Louis Zamperini passed away on July 2, 2014. He was able to watch a rough cut of the film on director Angelina Jolie's laptop while in the hospital before he passed.
While Zamperini and Phil are floating out at sea on the raft, the picture of a woman that Phil looks at is actually the real photo of his sweetheart and later wife, provided by his daughter to Angelina Jolie during filming.
Despite being a born-again Christian, Louis Zamperini requested that the film not delve too deeply into his religion, as he wanted his experiences with faith and forgiveness to reach the audience on a universal level.
Gunnar Höckert, the Finnish runner shown winning the gold medal in the 1936 Berlin Olympics was also a casualty of the Second World War. He went to the Winter War as a volunteer and was killed on the Karelian Isthmus just one day before his 30th birthday in February 1940.
Miyavi found performing the scene in which Zamperini is forced to hold a beam over his head at gunpoint so upsetting and intense that he vomited on set.
Universal Studios bought the rights to the story of Louis Zamperini in 1957 in the hope of developing it for Tony Curtis. In later years, Nicolas Cage expressed an interest. The project finally got the green light after Laura Hillenbrand's 2010 book about Zamperini became a best-seller.
After the war, Mutsuhiro Watanabe "The Bird" owned a vacation condominium on The Gold Coast in Australia, which is coincidentally where much of the movie was filmed.
Louis Zamperini became a devoted follower to Jesus Christ and went back to Japan and forgave those who hurt him while he was kept prisoner.
Left out of the movie is one of the most horrific aspects of the real postwar life of Louis Zamperini. Not only did he suffer from severe PTSD, depression and alcoholism, but also dealt with night terrors about strangling his Japanese captors. In 1948, during a particularly strong episode, Zamperini started strangling his pregnant wife, which made her file for divorce shortly after. It was the specific incident that made Zamperini finally seek help and the comfort of religion.
After the war, Louis Zamperini struggled for several years with PTSD and alcoholism. At the urging of his wife (she threatened to leave him), he attended an early Billy Graham crusade, rededicated his life to Christ, and forgave his captors. Inspired by Louie's powerful testimony, Graham helped him get started in a secondary career of public speaking.
It was widely thought that Louie Zamperini would be the first man to break the barrier for the first sub 4 minute mile. History stepped in the way however and that barrier was not broken until Roger Bannister did it in 1954.
Director Angelina Jolie and the real Louis Zamperini happened to live remarkably close to one another in the same Los Angeles neighborhood.
In his hometown of Torrance, the airport located in the southern part of the city is named after Louis Zamperini.
Based on the military insignias on both his uniform's right sleeve and hat at the end of the movie, Pete Zamperini was apparently a Chief Petty Officer in the United States Navy.
The film was shown at the Casina Pio IV, headquarters of the Pontifical Academy of Sciences and Pontifical Academy of Social Sciences, at the Vatican on January 8, 2015. Pope Francis, who was aware of Louis Zamperini's story, did not attend the screening, but did meet the film's director, Angelina Jolie, and Luke Zamperini, the late athlete's son, afterwards.
Not only the title of the film, but its tagline "Survival / Resilience / Redemption" are inspired by the book the film is based on, "Unbroken: A World War II Story of Survival, Resilience, and Redemption" by Laura Hillenbrand.
Director Angelina Jolie and cinematographer Roger Deakins claim that one of their biggest influences making the movie was the Sidney Lumet movie, The Hill (1965).
Dane DeHaan was one of the finalists to play Louis Zamperini, however in the end, Jack O'Connell was cast.
The plane in this film, as in the actual history, gained the nickname the Green Hornet, after the radio hero-who teamed with a Japanese partner.
A B-24's bombing altitude is typically about 20,000 to 25,000 feet. At that altitude, the air temperature is well below zero, yet the plane isn't heated, no crew members are wearing gloves, the bomb bay doors are open and Zamperini is touching bare metal everywhere without feeling discomfort.
The albatross and it being killed are plot points similar to the Samuel Taylor Coleridge poem "The Rime of the Ancient Mariner".