The reason the plot of the Arabian Nights tale wasn't used for the movie may have had something to do with the fact that in the original story, there are some 42 murders; the first is Ali Baba's cousin, and the other 41 are those of the 40 thieves themselves and, later, their ringleader, who arrives at Ali Baba's disguised as a merchant and thirsting for revenge. He is the last of the forty thieves to die. The others die when, after smuggling themselves into Ali Baba's house in wine casks, boiling hot water is poured into each of the casks.
Hulagu Khan was a real person--he was the brother of Kublai Khan, the conqueror of Asia, and the Mongol leader who conquered Iran and Baghdad, as shown in the movie. However, it's generally believed by most historians that he died of natural causes, not murder.
The movie does not follow the plot of the original story except in the scene where the 40 thieves are stuffed in jars and then brought to the palace as a gift for the villain, Hulagu Khan.
Although Sabu was originally cast as Jamiel, the actor was drafted and replaced with Turhan Bey.
Final film of Betty Lorraine.