The Tenth Doctor is the energetic, brilliant, and deeply emotional incarnation of the Doctor portrayed by David Tennant, a Time Lord who can pivot from gleeful curiosity to terrifying authority in the space of a heartbeat.

Emerging from the Ninth Doctor’s regeneration, Ten throws himself into the universe with Rose Tyler, later traveling alongside Martha Jones and Donna Noble while crossing paths with companions and enemies across time and space.

He loves humanity loudly.

That affection is one of his greatest strengths and one of his most dangerous weaknesses. The Tenth Doctor can be playful, compassionate, romantic, furious, arrogant, lonely, and occasionally convinced that being the cleverest person in the room gives him permission to decide too much for everyone else.

His adventures pit him against Daleks, Cybermen, the Master, Weeping Angels, the Family of Blood, and threats stretching across reality itself. Yet some of his most defining moments come from quieter losses, especially the companions he cannot keep and the consequences of refusing to let go.

The trainers help him run.

The coat helps him arrive dramatically.

And “Allons-y” usually means someone nearby is about to have a very complicated afternoon.