Zack Snyder first conceived this as a Star Wars movie, and pitched it to Lucasfilm shortly after it was bought by Disney in 2012, but it never got off the ground.
The story is influenced by Akira Kurosawa's Seven Samurai (1954), which is Zack Snyder's favorite film. Star Wars: Episode IV - A New Hope (1977) was also influenced by a Kurosawa film, specifically The Hidden Fortress (1958).
Sir Ian McKellen, Sir Patrick Stewart, Liam Neeson, Morgan Freeman and Anthony Daniels were considered to play Jimmy the Robot until Sir Anthony Hopkins was chosen.
Comparisons have been made between this film and Battle Beyond the Stars (1980), which was also inspired by Seven Samurai (1954) and Star Wars: Episode IV - A New Hope (1977). Both films involve a small community under threat from an evil empire, and a band of warriors gathered to protect it.
In addition to Star Wars: Episode IV - A New Hope (1977), Seven Samurai (1954), and The Magnificent Seven (1960), the film also borrows elements of Ultramarines: A Warhammer 40,000 Movie (2010) for example. The use of Latin names for imperial/royal institutions, the design of weapons and vehicles, and the quasi-religious elements.