Private Moor

David Troughton's first role in Doctor Who was an uncredited guard in Enemy of The World. This was followed by a small part in his father's last story, the War Games, as Private Moor, a soldier guarding prisoners in the American Civil War Zone.

King Peladon

His major role came in 1972, in Curse of Peladon, when he played King Peladon himself, a young king, misled by his advisors, who eventually gets it right and in the process falls in love with Jo, only to be rejected by her. In The Doctor's next visit to Peladon, his daughter rules, so we can only assume he got over it.

Peladon in Love