And here is a bit more:
"Epics are historical films that recreate past events. They are expensive and lavish to produce, because they require elaborate and panoramic settings, on-location filming, authentic period costumes, inflated action on a massive scale and large casts of characters. Biopic (biographical) films are often less lavish versions of the epic film.
Epics often rewrite history, suffering from inauthenticity, fictitious recreations, excessive religiosity, hard-to-follow details and characters, romantic dreamworlds, ostentatious vulgarity, political correctness, and leaden scripts. Accuracy is sometimes sacrificed: the chronology is telescoped or modified, and the political/historical forces take a back seat to the personalization and ideological slant of the story (i.e., the 'poetic license' of Oliver Stone's controversial JFK (1991) immediately comes to mind).
Epics often share elements of the more elaborate adventure films genre and swashbuckler subgenre (e.g., the Robin Hood tale of The Adventures of Robin Hood (1938)). They may be combined with other genre types too, including:
epic/historical westerns (i.e., Cimarron (1930), Dances with Wolves (1990))
epic science-fiction (i.e., Star Wars (1977))
epic/historical dramas (i.e., Bernardo Bertolucci's The Last Emperor (1987))
epic war films (i.e., The Longest Day (1962))
unconventional epics (i.e., Robert Altman's Nashville (1975))
auteur epics (i.e., Coppola's Apocalypse Now (1979), Warren Beatty's period film Reds (1981), and theatrical director Julie Taymor's adaptation of Shakespeare's Titus (1999) (Andronicus) - her debut film with innovative production design)
Epics have existed since the earliest days of American cinema, from D. W. Griffith's ground-breaking The Birth of a Nation (1915), to the giant Civil War epic and Best Picture winner Gone With The Wind (1939), to the fairly-recent Schindler's List (1993), Titanic (1997), and Ridley Scott's Best Picture winner and revamped 'sword and sandal' epic, Gladiator (2000) (with state-of-the-art CGI visual effects). Irreverent spoofs of Biblical films have also emerged, such as The Life of Brian (1979), with the Monty Python cast.
Epics are often called costume dramas, since they emphasize the trappings of a period setting: historical pageantry, costuming and wardrobes, locale, spectacle, decor and a sweeping visual style. They often transport viewers to other worlds or eras: ancient times, biblical times, the Middle Ages, the Victorian era, or turn-of-the-century America. Unlike true historical epics, period films choose a specific historical period, and then superimpose fictional characters or events into the setting. "