Director/producer Mel Gibson was investigated by an animal welfare organization, who were convinced that the fake horses used were real. Only when one of his assistants provided some videotaped footage of the location shooting were they convinced otherwise.
The extras used for the battle scenes were mostly members of the F.C.A., the Irish version of the territorial army. As they were drawn from many different army companies, and the members of these are usually drawn from the same locality, local rivalry between such companies is common. Apparently, some of the battle scenes seen in the movie are far more realistic than you might imagine, with rival companies actually using the occasion to try the beat the lard out of each other.
Screenwriter Randall Wallace had been visiting Edinburgh in 1983 to learn about his heritage when he came across a statue of William Wallace outside Edinburgh Castle; he had never heard of the 14th-century figure who shared his name but was intrigued enough by the stories told to him about "Scotland's greatest hero" to research the story as much as possible.
Randall Wallace had very little historical evidence to work with in regard to William Wallace's life; he has noted that even Churchill's definitive work "A History of the English Speaking Peoples" observed in only a single line that virtually no factual material survives about the Scottish leader. Because of this, Randall Wallace relied heavily on a 15th-century romantic poem by the Scottish writer Henry the Minstrel ("Blind Harry") in constructing his story.
Writer Randall Wallace initially planned to start the story with William Wallace as an adult and added the prologue of his childhood only as an afterthought. As the sequence was first written, Murran gave William a rose (rather than a thistle) at his father's burial; however, someone who read the script helpfully pointed out that the rose, being a traditional symbol of England, would be (to say the least) somewhat inappropriate as a prominent feature in the story.
Glen Nevis, the Scottish valley which served as the location for Wallace's childhood village, also enjoys the heaviest rainfall in Europe. During the six weeks spent filming in the area, only three days of sunshine occurred, during which the wedding scene was finished. The filmmakers resigned themselves to the fact that constant rain was inevitable, and opted to film scenes regardless of weather conditions.
Thin layers of latex were used to attach set elements to the ruins of Trim Castle in Ireland to give it an appearance more befitting its medieval origins while allowing the stone to be unharmed when the additions were removed.
Prince Edward (later King Edward II) was indeed the first English prince to carry the title Prince of Wales, although he did not marry Princess Isabella until 1308, after both Wallace (1305) and Edward I (1307) had died.
One of the film's weary extras reportedly mistook one of Gibson's children on the set for an errand boy, and asked him to bring a cup of tea. Gibson was within earshot, and nodded and whispered to his son, "Go get it."
There is an in-joke in the film that William Wallace's private time with Isabella led to the conception of Edward III. This could not have been the case, since Edward III was born almost ten years after Wallace died.
Despite the film being set in Scotland, and based on the life of a Scottish folk hero, the primary instrument heard throughout the soundtrack (most notably at William's father's funeral) are the Uilleann pipes, which are a smaller traditionally Irish version of bagpipes rather than the ubiquitous Great Highland Bagpipe.
Gibson, a notorious jokester, directed some scenes in an Elmer Fudd voice and even yelled, "CUT!" during Murron's funeral scene by putting his arm around the actress playing her mother and hollering, "Will you put a sock in it!" This caused the actress to go from crying in character to break character and laugh. Gibson also intentionally started a false rumor that Sophie Marceau was the daughter of noted French mime Marcel Marceau.
Mel Gibson, who had been heavily criticized for a December 1991 interview with a Spanish magazine, was accused of homophobia for the film's portrayal of the Prince of Wales (and future King Edward II) as an effeminate homosexual. It is strongly disputed whether Edward II, who fathered at least five children, was either homosexual or even bisexual at all. The scene where Edward I threw his son's lover out of a castle window was particularly criticized for inciting homophobia. The lover was based on Piers Gaveston, who was allegedly Edward II's lover although he was also married and many historians believe these were just rumours invented by the King's enemies in order to discredit him. Gibson refused to apologize for the controversy in a 1995 interview with "Playboy" magazine while promoting the movie. However, in January 1997 he did agree to host a summit for representatives of gay rights organization GLAAD (Gay and Lesbian Alliance Against Defamation) on the set of Conspiracy Theory. Although the leaders of GLAAD noted they were disappointed that he did not apologize to them for the film's alleged homophobia, Gibson did acknowledge "regret" over his controversial 1991 interview, claiming he had been drinking at the time and that his words had frequently been used to criticize him.
While the movie took great care to depict several groups all dressed alike in their representative tartans (the plaid pattern on the kilts), the use of clan tartans and any organized rules for kilts and patterns was a Victorian invention, much later than the time of the movie.
The Gaelic chant is "Alba gu brath", which means Scotland forever. Although Wallace was a Lowlander, many of his troops were Highlanders, and a large part of the Lowlands were still Gaelic speaking at this time in history.
The rough cut of the film initially contained much more violence than the final product. Fearing an NC-17 from the MPAA after negative test reaction, Mel Gibson went back and personally edited some of the film's most graphic scenes to show the brutality more off-screen, rather than on.
William Wallace gives a speech in which he says the famous quote "Every man dies - Not every man really lives." This famous quote commonly attributed to the "Braveheart" character was actually authored by a 19th Century American Poet whose name was William Ross Wallace, famous for writing the poem "The Hand That Rocks The Cradle Is The Hand That Rules The World", who is of no relation to the William Wallace in the film.
Although the majority of the characters in the film are Scottish, the actors portraying them were mostly drawn from non-Scottish parts of the UK (exceptions to this rule include Angus Macfadyen (Robert the Bruce) and Brian Cox (Argyle)). Ironically, the one Irish character in the film (Stephen), is played by Scots-born David O'Hara.
In an October 2009 interview with "The Daily Mail", Mel Gibson admitted that the film was heavily fictitious but claimed the changes had been made for dramatic purposes. He also admitted he had always felt he was at least a decade too old to play Wallace.
When the members of Clan MacGregor attempt to join Wallace's rebellion against the English, the MacGregor chieftain mildly insults Wallace and his men by calling them "Amadans". "Amadan" is both Scots Gaelic and Irish Gaelic for "fool" or "idiot". Thus, the MacGregor chieftain is calling Wallace and his men fools, both for resisting the English and for not inviting the MacGregors to participate in the rebellion.
Shortly after Wallace is knighted, an elderly member of Clan Balliol (portrayed by Bernard Horsfall) asks Wallace about the Balliol claim to the throne of Scotland. In real life, John Balliol became King of Scotland in 1292, but was deposed by King Edward I of England in 1296. The real William Wallace swore his loyalty to King John Balliol, even after Balliol was imprisoned in England.
At the Battle of Falkirk (July 22, 1298), the English army was personally led by King Edward I, who decisively defeated the Scots. The real-life King Edward I was a military genius who learned combat tactics while fighting the Mamelukes during the Eighth and Ninth Crusades.
The trivia items below may give away important plot points.
In the movie Wallace is jumped, beaten down, and captured at Edinburgh Castle, betrayed by Robert Bruce the Elder; in real-life, Wallace was betrayed by a Scottish nobleman loyal to King Edward, Sir John Menteith. Wallace was captured at what is now Rob Royston (named for another legendary Scottish hero, Rob Roy MacGregor), a suburb of Glasgow.
Elder Campbell is wounded in every battle he is seen participating in. He takes an arrow in the chest during the initial uprising against the local magistrate, his hand is cut off during the Battle of Stirling Bridge, and finally he takes an axe to the gut during the battle of Falkirk.