It Clicked

I love it when it happens. It's at a different age for each kid I'm discovering, but you can almost hear the click in their brain. CLICK. They discover the joy of reading and will pick up a book on their own and lose themselves in the adventure. Caleb's brain just CLICKed. The challenge now is find him good stories with good character, good morals, and a God-glorifying storyline. Any suggestions for an adventure-seeking boy who would have done well to have grown up in the Middle Ages?