The
Tenth Doctor is an incarnation of
the Doctor, the protagonist of the
BBC science fiction television programme
Doctor Who, who is played by
David Tennant in three series as well as nine specials. As with previous incarnations of the Doctor, the character has also appeared in other
Doctor Who spin-offs. In the programme's narrative,
the Doctor is a centuries-old
Time Lord alien from the planet
Gallifrey who
travels in time in his
TARDIS, frequently with
companions. When the Doctor is critically injured beyond medical repair, he can
regenerate his body; in doing so, his physical appearance and personality change, and a new actor assumes the role. Tennant's portrayal of the Doctor is of an outwardly charismatic and charming adventurer whose likeable and easygoing attitude can quickly turn to righteous fury.