The protagonist, is a ruler of a kingdom, but is suddenly attacked by a neighboring kingdom. The king has two flaws. He is overconfident, in both his ability and the army. He is also more involved with living in pleasure rather than to work. Creating problems for him in his administration and political arena.
Passion: Have always wanted to write a medieval themed novel.
Plot: The kingdom is attacked by a neighboring kingdom, and conquered before the protagonist could overcome his flaws.
Story: The king sees his flaws and begins to make the right decisions too late.
Theme: There are often no real bad guys in conflict. Only conflicting agendas.
What if a (flawed protagonist) (encounters some problem) and has to (overcome the flaw) to (solve the problem)?
What if a king, who is overconfident and unattended to state matters suddenly is forced via war to be roused out of them but is unable to do so in time? Bringing about the loss of all he inherited.