David Campbell Junior

David Campbell Junior was the youngest adopted son of David Campbell Senior and his Gallifreyan wife, Susan Campbell.

Biography
He was orphaned in the Dalek Invasion of Earth in the 22nd century, and sometime after the human victory, he 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. Some time after the three orphans were adopted, David and Susan concieved a child who they named Alex Campbell.