Prophecy

During the course of Doctor Who, many prophecies have been made by those with physcic abilities.

Evelina and Lucius Petrus Dextrus
During their time in Pompeii, the Doctor and Donna end up encountering Evelina and Lucius Petrus Dextrus who both posses telepathic abilities as a result of the Pyrovillies and as a result of a crack in time opened by Vesuvius' eruption, posses the ability to see into the future. As a result, they make some startling prophecies about the Doctor and Donna's futures and pasts.

Evelina

 * Evelina is able to tell that the Doctor and Donna aren't who they say they are and that the Doctor's name is Doctor and not Spartacus as he tells him and that Donna calls herself Noble (her last name). She is also able to tell that both came from far away.
 * Evelina also predicts that the Doctor's name is false and that his true name is hidden in the Cascade of Medusa herself.
 * Evelina is also able to predict the Doctor's true nature.

Lucius

 * When pressed, Lucius is able to tell that the Doctor is from Gallifrey and Donna from London.
 * Another prediction of his is to the Doctor: "she is returning" something that is unclear at the time.
 * He predicts that Donna has "something on her back" which startles her, but is something not understood at the time.

Fulfillment

 * Evelina's prediction about the Doctor's name is likely about the Medusa Cascade and how there Davros named the Doctor the "Destroyer of Worlds."
 * Lucius's prediction about she is returning refers to Rose Tyler's return, which is something that is happening throughout series 4 but is unclear until Turn Left.
 * Lucius' prediction that she has something on her back comes true in Turn Left: a Time Beetle attaches itself to her back and she ends up with many people pointing that out to her alternate self until she gets rid of it by changing time with Rose Tyler's help.

Dalek Caan
Due to travling into the Time War, Dalek Caan gains the ability to see into the future, but it also drives him insane. As well as making some prophecies, he works to make them come true as he realizes how evil his race is.

Prophecies

 * Dalek Caan predicts that the Doctor is coming and refers to him as the "three-fold man."
 * Dalek Caan predicts that the Doctor's Children of Time will gather and that the most faithfull one will die. He predicts this repeatedly, his last words being "one will still die" as his final prophecy.
 * Dalek Caan also predicts that the Doctor's true soul will be revealed.
 * Dalek Caan predicts the end of the Dalek race due to their evil and foresees that the Doctor will be the one to do it.

Fullfilment

 * Dalek Caan's prophecy of the Doctor as the "three-fold man" ends up refering to the three Doctors that converge to stop the Daleks: the Tenth Doctor, the Meta-Crisis Tenth Doctor and the DoctorDonna.
 * The Doctor's companions gather to aid him in dealing with the Daleks, summoning him and aiding him in battle. While none actually die, Donna Noble's memory is erased to protect her as her Time Lord side is too much for her and the person she became due to the Doctor essentialy dies.
 * Davros claims that when the Doctor's companions threaten mass destruction to stop the Daleks that the truth about the Doctor is revealed: he is a man that refuses to use a weapon, but molds his companions into ones.
 * Dalek Caan pushes the Meta-Crisis Tenth Doctor to fulfil the prophcy about the Daleks destruction and causes him to realize it needs to be done. With Dalek Caan's insistance, the Clone Doctor destroys the Daleks.

Carmen
Carmen naturally posseses low-level telepathic powers which seemed to be enhanced as a result of her visit to San Helios. As a result of her powers, she makes a startling prophecy which the Doctor realizes predicts his death.

Prophecy
As she says goodbye to the Doctor, Carmen makes a prophecy about his future telling him "your song is ending sir.... it is returning through the dark, and then Doctor..... oh but then he will knock four times."

Fulfillment
The Doctor does everything he can to stop this prophecy from happening, even electrocuting Andy to prevent him from knocking four times, but it proves invetiable. Eventually when The Master is responsible for bringing back the Time Lords, the Doctor realizes what "it" is: as a result of breaking the time-lock on the Time War, the Master has brought back more than the Time Lords, he has brought back Gallifrey, the "it" from Carmen's prophecy that was returning. Gallifrey ends up returning in orbit of Earth and nearly destroys Earth. After the Doctor and the Master defeat the Time Lords and banish them and Gallifrey back into the Time War, the Doctor believes that he is safe and has averted the rest of the prophecy when four knocks sound. It turns out that "he" is the Doctor's companion Wilfred Mott who knocks four times repeatedly to get the Doctor's attention in order to be set free from a radiation booth he got trapped in freeing a man. In order to save him, the Doctor must sacrifice himself and absorb a fatal dose of radiation or let Wilfred absorb it and die. The Doctor saves Wilfred which causes him to absorb the fatal dose of radiation and eventually regenerate. Thus the Tenth Doctor dies and the Eleventh Doctor is born.