Writing historical novels very often leads to discovering new favourites. When I started writing my The King’s Greatest Enemy series, I was very much into Roger Mortimer and Queen Isabella, only occasionally sparing a thought for Isabella’s son, the very young Edward III who became an unwilling participant in the events that led up to his father’s deposition and subsequent (purported) death.

As my writing progressed, Edward grew on me. The idea of a young boy torn in two by his love for both...