The Ninth Doctor was the ninth incarnation of The Doctor in the modern Doctor Who.
The Ninth Doctor was the direct survivor of the Last Great Time War and the very last of the Time Lords, but left the conflict with the excruciating knowledge of his hand in its grisly conclusion. Now cut off from the Time Lord race, the Doctor found himself alone and bereaved. Emotionally haunted by the war, he entered a darker period of his life spattered by resentment, where he tended to brood and act crossly to those who rubbed him the wrong way. Despite this, he remained jovial and quite friendly towards anyone he took a liking to, slowly reasserting himself as the Doctor while letting go of his lingering wartime persona.
He was killed by absorbing Time Vortex energy from his companion Rose Tyler in order to save her life, destroyed his own body's cells in the process. He regenerated into the Tenth Doctor.