Darth

"Henceforth, you shall be known as Darth&hellip; Vader."

- Darth Sidious, upon making Anakin Skywalker his new apprentice

Darth was a title given to the Sith Lords of the Sith Order, which preceded a moniker different from the birth name. It roughly translated to "Dark Lord." The Sith names of Sheev Palpatine, Count Dooku, and Anakin Skywalker were Darth Sidious, Darth Tyranus, and Darth Vader, respectively.

Era of the Sith
During a time when the Sith were plentiful and powerful, a male Sith Lord, Darth Atrius, was a bearer of the Darth title.

A former member of the Jedi Order, Radaki became part of what was later known as the Lost Twenty and was seduced by the dark side of the Force as a result of his belief that the Jedi should retain their family ties and wealth. Having forsaken his allegiance to the Order, he adopted the name of Darth Krall and became a powerful Sith Lord.

The Phantom Menace
Years after the full-scale Jedi–Sith war, when Sith Lords were destroyed by the Jedi, Darth Bane&mdash;the sole Sith Lord survivor&mdash;established the Rule of Two and restored the title. In at least two cases (those of Count Dooku and Anakin Skywalker), the Darth title and the accompanying moniker were bestowed onto the Sith apprentice by the Master.

Imperial Era
The Jedi Master Obi-Wan Kenobi used "Darth" as a form of address when talking to Darth Vader in 0 BBY during the Rescue of Princess Leia.

Ancient Sith

 * Darth Atrius
 * Darth Caldoth
 * Darth Krall
 * Darth Wrend

The Rule of Two

 * Darth Bane
 * Darth Plagueis
 * Darth Sidious
 * Darth Maul
 * Darth Tyranus
 * Darth Vader

Non-Canon Appearances

 * Star Wars Epic Yarns: A New Hope
 * Star Wars Epic Yarns: The Empire Strikes Back
 * Star Wars Epic Yarns: Return of the Jedi
 * LEGO Star Wars: Droid Tales Episodes I-III