Why was episode 1 called the phantom menace?

In the Star Wars franchise, the term "phantom menace" refers to a hidden or unseen threat that poses a significant danger. In Episode I: The Phantom Menace, the title alludes to the Sith Lord Darth Sidious, who operates in secret as the mastermind behind the Trade Federation's blockade of the planet Naboo. Sidious manipulates events from the shadows, orchestrating various conflicts and using his apprentice, Darth Maul, to carry out his plans.

The title emphasizes the secretive nature of the threat posed by Sidious and the impending danger it represents to the galaxy.