The letter “J” was the last letter added to the alphabet and probably wouldn’t have been a part of the crusaders’ trap.

In Indiana Jones and the Last Crusade Indy has to retrieve the Holy Grail in order to stop the Nazis and save his father – a classic MacGuffin. Between him and the Grail however are a series of traps constructed by knights of the First Crusade. One of these traps is a floor with flat stones individually marked with various letters of the alphabet. He is “to proceed in the footsteps of the word” and only step on the floor stones that spell the name of God. The name of God in this case is Jehovah but Indy makes the mistake of stepping on the letter “J” whereby the floor crumbles. He then remembers that in the Latin alphabet the first letter in the name Jehovah is actually an “I”.

the last letter of the alphabet

Jehovah in Latin was originally spelled “Iehouah” with a capital “I” because the letter “J” hadn’t been invented yet. This also means that Jesus’s name wasn’t “Jesus” in his lifetime. In Hebrew he was Yeshua or Yehoshua, or in Aramaic he was Isho or Yeshu. For a long time the letter “J” was just a fancy way of writing the letter “I”. It wasn’t until 1524 that Italian grammarian Gian Giorgio Trissino proposed separating the two letter forms to become two separate letters with two separate sounds, and in so doing made the letter “J” the last letter added to our alphabet.

This raises a typographical problem with the film. The letter “J” is part of the trap but it didn’t become a part of the alphabet until after 1524, a few hundred years after the First Crusade which was from 1096-1099. So we have to conclude that either:

• the knights didn’t build the trap for more than 400 years after the First Crusade, or …
• every now and then the immortal knight of the Grail updates the trap to include new letter forms over the centuries to keep the trap up to date with the times, or …
• the writers of Indiana Jones and the Last Crusade didn’t do much alphabet research and incredibly audiences were willing to overlook such a flagrant error.