There are many themes in The Castles of Athlin and Dunbayne; in the first half of the book, revenge, loyalty and unity, are the most important. Because of these three feelings, most of the actions of the book happen. Both Earl Osbert and Baron Malcolm are acting off of revenge. Malcolm killed Osbert's father, because he is a violent man. Osbert wants revenge, so he launches an attack on Malcolm. When Osbert gets captured, Malcolm wants to get back at Osbert, with revenge, either directly or through his family; so Malcolm gives Miranda, Osbert's mom, a choice: either Malcolm marries Mary, Osbert's sister, or Osbert is killed. That's one of his main plans for revenge. Besides Malcolm's plan showing revenge, it also shows Mary's loyalty for
