Valda was the leader of the Thains in the 30th century.
Valda's people were attacked by Kleptons, who captured many as slaves. The First Doctor, John and Gillian arrived and after driving off some Kleptons, met with Valda, who explained the situation. They encouraged him and his people to fight back, and were taken to a museum of old weapons, which were used to repel the invaders. (COMIC: The Klepton Parasites [+]Loading...["The Klepton Parasites (comic story)"])