Contrary to popular conception, the title of the film does not refer to Nathan Algren, or even Katsumoto, as the Last Samurai. The word "Samurai" here is in its plural form and is actually referring to Katsumoto's clan as a whole.
Japan's first Caucasian samurai was actually an Englishman named William Adams, born in 1564 in Gillingham, Kent, UK. He was a sailor and fought the Spanish Armada not long before he left for the Far East, when he eventually was taken prisoner by samurai and refused to leave Japan because of his ship-making qualities. Lord Ieyasu gave him two swords, the trademark of a samurai, because he was a great asset to Ieyasu. Adams' story was more directly adapted/dramatized as the character of John Blackthorne/Anjin-san in James Clavell's novel "Shogun", filmed as Shogun (1980).
Tom Cruise narrowly escaped potentially fatal injuries after a sword was swung within one inch of his neck while filming. He and his co-star Hiroyuki Sanada were acting out a sword fight scene when the incident happened. Sanada swung a sword at Cruise who was on an off-camera mechanical horse at the time. But the machine reportedly malfunctioned and failed to duck at the right moment. Sanada stopped the blade just one inch from his neck.
Filming took place in New Zealand, mostly in the Taranaki region, with Japanese cast members and an American production crew. This location was chosen due to the fact that Egmont/Mt. Taranaki resembles Mt. Fuji, and also because there is a lot of forest and farmland in the Taranaki region. This acted as a backdrop for many scenes, as opposed to the built-up cities of Japan. Several of the village scenes were shot on the Warner Brothers back lot in Burbank, CA. Some scenes were shot in Kyoto and Himeji, Japan. There were 13 locations altogether.
Critical reception in Japan was generally positive. Tomomi Katsuta of "The Mainichi Shinbun" thought that the film was "a vast improvement over previous American attempts to portray Japan", noting that director Edward Zwick "had researched Japanese history, cast well-known Japanese actors and consulted dialogue coaches to make sure he didn't confuse the casual and formal categories of Japanese speech." However, Katsuta still found fault with the film's idealistic, "storybook" portrayal of the samurai, stating: "Our image of samurai is that they were more corrupt." As such, he said, the noble samurai leader Katsumoto "set [his] teeth on edge."
Historically, the only westerners fighting in the Japanese civil war were French military advisers under Jules Brunet who joined the Shogun's army. Even if most of them were fighting with French equipment, some did wear the samurai attire (like Eugene Collache).
This film was inspired by a project developed by writer / director Vincent Ward. Ward became executive producer on the film, working in development on it for nearly four years. After approaching several directors (among them Francis Ford Coppola, Peter Weir), he interested Edward Zwick. The film went ahead with Zwick as director and was shot in Ward's native New Zealand.
When Algren finds out that he killed Katsumoto's brother-in-law, Katsumoto replies, "It was a good death." This is also the final line in the Edward Zwick-directed movie Legends of the Fall (1994), with the narrator referencing Tristan Ludlow's (played by Brad Pitt) death fighting a grizzly bear.
First feature to use the new Kodak Vision2 500T 5218 film stock - the successor of the previous Vision 500T 5279. However, it was released later than Seabiscuit (2003) which uses the same film stock but at a later date.
The trivia items below may give away important plot points.
The real-life counterpart to Katsumoto (played by 'Ken Watanabe') is Takamori Saigo, who led a samurai rebellion in 1877. As in the movie, Saigo ended up committing suicide in September 1877 after defeat in battle. The Emperor's attitude in the film toward Katsumoto's struggle and death reflects actual Japanese popular sentiment toward Saigo, who though defeated, was regarded as a hero; a statue of Saigo was erected shortly after his death, and can today be seen in Ueno, in northeast Tokyo.
When Taka starts to undress for Capt. Algren there is a shot with her clothes slightly below her shoulders looking backwards over her shoulder. This is an homage to Hishikawa Moronobu's ukiyo-e painting "Backwards Beauty".
At the beginning of the movie the Japanese soldiers who are trained by the Americans are using American-made Model 1861 Springfield muskets and British-made Pattern 1853 Enfield muskets, no doubt surplus from the American Civil War (which ended 11 years before the beginning of the movie). At the final battle, however, the now better trained and better equipped army can be seen using Prussian-made Gewehr 1871 bolt-action Mausers, a single-shot, bolt-action, black-powder cartridge rifle. This rifle, unlike modern bolt-action rifles, had no magazine (the Model 1871/84 would add a tubular magazine). This equipment update is also reflected in the dress of the Japanese soldiers, which abandoned the American 1870s look of the first part of the movie and adopted a stern, militaristic Prussian look (dark blue blouse, white gaiters, the more military style cap of a professional army instead of a French-style kepi then used by the US army). This is because the elite Japanese units during this time were trained by Prussia, and the Model 1871 Mauser was widely exported during the 1870s-1880s and was not fully replaced even in Prussian/German service until 1889.