David Campbell Junior

David Campbell Junior was the youngest adopted son of David Campbell Senior and his Time Lord wife, Susan Campbell. He was the great-grandson of the Doctor.

Biography
David was orphaned during the Dalek Invasion of Earth in the 22nd century, and sometime after the human victory, was adopted by David and Susan. They had already adopted two orphans before him.

David Junior was named after his adopted father. His adopted brother and sister were named after Ian Chesterton and Barbara Wright, who were both former companions of Susan's grandfather, the First Doctor. (PROSE: Legacy of the Daleks) Some time after the three orphans were adopted, David and Susan conceived a child whom they named Alex Campbell. (AUDIO: An Earthly Child)