Johnny Chess

Johnny Chess was the stage name of John Alydon Ganatus Chesterton, the son of Ian Chesterton and Barbara Wright. His unusual middle names came about because Ian and Barbara named him, in part, as a memorial to Alydon and Ganatus, Thals whom they had encountered during their visit to Skaro. Ace admired him, mostly from afar, but did manage to interact with him. (PROSE: Timewyrm: Revelation, PROSE: Byzantium!)

Behind the scenes
Johnny Chess originated as a fan fiction character dating from the days before Paul Cornell and Keith Topping had published professional Doctor Who fiction. In the stories, he marries and divorces Tegan Jovanka. (REF: I, Who 3)