For the scene at the Nazi rally in Berlin (where Indy confronts Elsa and steals back the diary), Steven Spielberg had all the extras who did the "Sieg Heil" arm salute also put their other arms behind their backs and cross their fingers.
In the scene where Indy has to choose which cup is the grail, he picks the right one by saying "That's the cup of a carpenter". It is said in the Bible that Jesus - like his mortal father Joseph - was a carpenter. Interestingly, as a struggling actor Harrison Ford used a book on carpentry from the library to start doing odd jobs and earn a living. He was working on George Lucas' house.
Most of the uniforms worn by the Nazis in the Berlin book burning scene are authentic WW2 uniforms and not costumes. A cache of old uniforms was found in Germany and obtained by costume designer Anthony Powell to be used in the film.
Harrison Ford nominated River Phoenix to play him as a teenager. When describing how he prepared for playing the role, Phoenix explained that he didn't really base his portrayal on the Indiana Jones character, but on Harrison Ford. So he observed Ford out of character before acting his part.
When George Lucas met with Steven Spielberg to discuss a third Indiana Jones movie, he wanted to have it set in a haunted mansion. Spielberg had just finished Poltergeist (1982) and decided that he wanted to do something different. Lucas then came up with the idea of the Holy Grail and Spielberg added the idea of a father/son sub-story.
Henry Jones senior was, according to backstory material written but not presented in the film, born in the 1860s, and was a Scottish university professor before emigrating to Utah, where Indy was born. He was roughly 75 years old in 1938. Sean Connery was only 58 at the time of filming (and only 12 years older than Harrison Ford), hence the beard and general "old man" attire his character wears. Indy impersonating a Scottish lord at Castle Brunwald was a nod to this unspoken backstory.
Indy's trademark hat, jacket, and whip currently reside in the Smithsonian National Museum of American History. These items remained on display during filming of Indiana Jones and the Kingdom of the Crystal Skull (2008), as they used numerous duplicates for their prop costumes.
When Tom Stoppard was brought in for rewriting the dialogue, specifically the lines for Henry and the Henry-Indy exchange. He was paid $120,000. After the film's release and success, he was paid another $1 million as a bonus. In "The Last Crusade: An Oral History," an article published in Empire magazine in 2006, Spielberg said about the Jr. and Sr. conversations, "It was an emotional story but I didn't want to get sentimental. Their disconnection from each other was the basis for a lot of comedy. And it gave Tom Stoppard, who was uncredited, a lot to write. Tom is pretty much responsible for every line of dialogue."
The temple right at the end of the movie exists, but not in Alexandretta. It is in Petra, in Jordan. However, there is no inside to it - the doorway that can be seen on screen is huge, eight or nine people shoulder to shoulder can easily walk through it. It leads to a huge empty square room carved from the top down over two stories high. Similarly, they would be unable to get "lost" down the valley as the valley stretches for about a mile or so, and there is no other route but out. The filming at Petra was visited by Queen Noor and her children.
The character named "Fedora" in the credits (played by Richard Young) was in the script originally named Abner Ravenwood, Marion Ravenwood's father and Indiana's mentor who was mentioned in Raiders of the Lost Ark (1981).
When Dr Jones Sr. scares the "seagulls" to fly up and stop the plane, they are in fact pigeons, and not seagulls, as seagulls are not trainable. If you look closely you can also see that there are a number of 'cut out' seagulls in the sand, which do not move as the others do.
During the Castle Brunwald rescue, Dr. Jones Sr. expresses dismay at Indy inadvertently bringing the diary into enemy hands saying that he "should have mailed it to The Marx Brothers". Harpo Marx revealed in his autobiography that he once really had to smuggle a journal of important documents out of Russia to keep them from falling into enemy hands.
First Indiana Jones movie to receive a PG-13 rating by the MPAA. Although Indiana Jones and the Temple of Doom (1984) was instrumental in the development of the PG-13 rating, the MPAA only gave it a PG-rating.
When Henry climbs into the tank to rescue Marcus, he taps Marcus on the shoulder (scaring him in the process), after which Henry says "Genius of the restoration...", to which Marcus replies with "...aid our own resuscitation!" That particular phrase was originally an old toast that was traditionally given at the University Club in Manhattan.
Chris Columbus wrote a rejected draft in which Indy traveled to Africa and dueled a Monkey prince, but the script was also rejected because of too many negative African stereotypes. However, the tank chase sequence in the film was taken from his draft.
River Phoenix becomes the first actor to portray Indiana Jones as a teenager. The prologue sequence featuring young Indy inspired George Lucas to create the TV series The Young Indiana Jones Chronicles (1992) released three years later. Phoenix was asked to play young Indy in that series, but turned it down, since he didn't want to return to television.
Unable to keep his hat on during the scene where he was chasing the tank on horseback despite trying glue, tape, and newspaper wedges, Harrison Ford pretended (in a "Making Of" special) to staple the hat to his head.
In the movie the grail is located in the Republic of Hatay near the city of Alexandretta. There actually was a Republic of Hatay from 1938 to 1939, after the region was granted independence from French Syria and before it became a province of Turkey. The capital of Hatay was Alexandretta before 1939 when the city's name was changed to Iskenderun and the capital moved to Antioch. An early title indicates the movie's action takes place in 1938.
Both tanks (the hero tank for full shots and process tank for closeups of action) now reside at the Disney's Hollywood Studios (formerly the Disney/MGM Studios) in Disney World in Florida, although the process tank is no longer on display.
In the beginning of the film when Harrison Ford is teaching his class, he says, "...If it's truth you're interested in, Dr. Tyree's philosophy class is right down the hall." This is a reference to Ford's own professor (Ford was in fact a Philosophy major), Dr. William E. Tyree, at Ripon College, Ripon, WI.
When it came to filming the rat scene, the producers inquired of their insurer, Fireman's Fund, whether they were insured if the animals were for some reason indisposed, due to illness, an accident, or simply because they refused to perform. This was a delicate issue, as one lost day of filming can cost hundreds of thousands of dollars, yet the experts at Fireman's Fund were able to reach a compromise which pleased both sides. They asked the director what would be the least number of rats needed for a dramatic shot. If different camera angles were used, 1,000 rats would probably be sufficient, came the answer. Thus Fireman's Fund underwrote the world's first insurance policy with a 1,000-rat deductible. 1000 mechanical rats were also used in the scene. To help achieve the sound of thousands of rats, sound designer Ben Burtt actually used the higher registers of thousands of chickens.
According to the address on the package he received from Italy, Indy teaches at Barnett College. The name of the school was adopted and more prominently used in later media (e.g. Indiana Jones and the Fate of Atlantis (1992))
A sign leading up to the tribune at the rally says "Staff Officers only" ("Nur für Stab(s)offiziere", which in German means the rank of major or higher), which is probably why Indy chose the rather conspicuous uniform of a colonel.
The difficulties shown by the tank-driver in maneuvering the vehicle were very realistic. The Mark I tank --or indeed, any World War I tank-- was so unwieldy that its manufacturers rushed to produce an upgrade; the Mark IV was ready in only one year's time.
After fleeing Castle Brunwald and eluding the Nazi soldiers on motorcycles, Indy and his father come to a fork in the road with a sign indicating left (North) to Berlin and right (South) to Venice. A third city is barely visible on that same sign, pointing at the direction the Joneses just came from, and it indicates the road to Garmisch-Partenkirchen, which hosted the 1936 Winter Olympics.
The idea of an airplane being carried by an airship was actually taken from the U.S. Navy airships U.S.S. Akron and U.S.S. Macon. Each airship, slightly smaller than the Zeppelin shown in the movie, actually had a trapeze (also known as a "sky hook") under the belly of the airship, and hangar space inside for up to four small planes. The planes were intended to act as scouts that used the airship as a flying aircraft carrier. The builders of the Hindenburg also attempted, with help from the Navy, to install a similar trapeze on the Hindenburg shortly before her disastrous last flight in 1937. The idea was for the small plane to act as a mail courier. However, the pilot was unable to "hook on" to the trapeze consistently, the experiment was abandoned, and the trapeze was removed from the Hindenburg before she departed for her final flight. In The Great Waldo Pepper (1975), the character of Kessler was based on that pilot, WW1 German ace Gen. Ernst Udet.
Harrison Ford (Indiana Jones) and Pat Roach (Gestapo) are the only actors to appear in all three films in the original trilogy. Roach played Giant Sherpa/First Mechanic in Raiders of the Lost Ark (1981)' and Chief Guard in Indiana Jones and the Temple of Doom (1984). A scene was filmed where Indiana Jones knocks him unconscious aboard the zeppelin, extending a running joke in the series of Ford's character knocking down Roach's characters in every movie; however, the scene was not used in the final cut, so the only presence of Roach remaining in the movie is the shot of him running behind Vogel toward the zeppelin. "Indiana Jones and the Last Crusade" is also the last film in the franchise with Roach, who would pass away in 2004.
Henry Jones Sr. calls Indy "Junior" 16 times. He calls him Indiana only twice. He also calls Indy "son" 4 times and "boy" twice. Indiana tells his father not to "call him Junior" (or that) 3 times, and almost does a 4th but was interrupted. Indiana calls his father "dad" a total of 54 times, 4 times when his father isn't there.
Although all of the scenes involving the Frederick Jaeger character were cut from the film, he can still be seen in the background of one shot set inside the Berlin airport. Billy J. Mitchell and Jerry Harte, despite being credited in the end titles, were cut out of the final print.
The tank that Indy fights is a replica of a British/American Mark VIII, manufactured in 1918. Its armament consisted of two six-pound guns and seven machine guns; only 107 were produced due to the end of the war. The tank shown in the film has a turret replacing the large cupola for the commander/driver, and no machine guns; it is also much faster than the real Mk VIII's.
Donovan's death sequence by rapid aging was the first all-digital composite. In previous films involving computer generated visual effects (i.e., Young Sherlock Holmes (1985) and Willow (1988)) CG elements were output to film and added to final film print using optical printers. For "Last Crusade" ILM scanned several filmed makeup transformations of "Donovan's demise" and "morphed" the elements together digitally. By doing this, film (was for first time) scanned, digitally manipulated, and output back to film rather than arranging film elements with an optical printer. It took a week to film this death scene.
Indy's true name is finally revealed in this movie: Henry Jones, Jr. In the previous two films (and in this film, up until the final minute), he has only been referred to as "Indiana Jones" and variations thereof. ("Dr. Jones", "Indy", etc.) The name Indiana came from a dog in both the movie and real life: George Lucas' Alaskan malamute dog who lived in the 1970s. A dog of this breed is seen in the film when young Indy (River Phoenix) returns home with the cross in his hand.