Lycon was the tutor of King Mihal of Zalezna.
When Mihal's uncle Kalem killed King Loran, Mihal and Lycon fled. They were caught by Kalem and his men but were saved by the Eighth Doctor, who used his sonic screwdriver to disarm the soldiers. Mihal was then made king of Zalezna.
Lycon later told Mihal's grandchildren the story of how Mihal became king while Mihal was on his deathbed. (PROSE: From Little Acorns)