Third Doctor

The Third Doctor was an iteration of the Doctor.

Biography

The Third Doctor played a part with an event involving the Uxariean Doomsday Weapon. (Colony in Space (TV story), He Jests at Scars... (audio story))

The Valeyard’s Theft and Use of the Doomsday Weapon

The Valeyard went to Uxarieus in the year 1471. He murdered all of the Uxarieans and stole the Doomsday Weapon. He then used it on Gallifrey because the Time Lords discovered how dangerous he can be. (He Jests at Scars... (audio story))

The Valeyard’s Course Corrections

At some point, the Third Doctor met the Valeyard. (He Jests at Scars... (audio story))

Possible Erasure or Death

The Valeyard told Mel that he unintentionally destroyed possibilities in which he exists, which can imply that the Third Doctor was either erased or killed. (He Jests at Scars... (audio story))