Echoing from the river bottom forest, the bark of the bog owl speaks of wild places still untamed, of quests not yet pursued, of great deeds not yet done. 

Aidan Errolson heeds this call of the wild . . . and soon learns it's a call to save his country. 

Twelve-year-old Aidan Errolson comes from a long line of adventurers. His grandparents were among the first settlers of Corenwald's eastern frontier. His father had been one of the kingdom's greatest warriors. Aidan, on the other hand, lives the quiet, comfortable life of a nobleman's son. He never has any real adventures, and that, he believes, is the one great injustice of his otherwise happy life. 

All that will change the day he first hears the bark of the bog owl and meets Dobro Turtlebane. Dobro is one of the feechiefolk—a tribe of half-civilized swamp dwellers who fight too much, laugh too loud, cry too easily, and smell just terrible. 

But another meeting on that remarkable day may change Aidan's life even more profoundly. Bayard the Truthspeaker arrives with a startling pronouncement: Aidan Errolson will grow to be the Wilderking—the long-prophesied wild man who will come out of Corenwald's forests and swamps to lead the kingdom back to its former glory.

There's only one question: Is Bayard the Truthspeaker a prophet or a madman?

From the dust jacket

Courage and a heart for adventure drive twelve-year-old shepherd boy Aidan Errolson. When the bark of the bog owl echoes from the forest across his father's well-tended pastures, Aidan dreams of wild places still untamed and quests not yet pursued. 

Aidan's life changes forever on the day Bayard the Truthspeaker arrives at Longleaf Manor with an astonishing pronouncement: it is Aidan's destiny to be the Wilderking, who will ascend to the throne from Corenwald's wildest places. Only the Wilderking can balance his people's civilizing impulses with the wildness that gives Corenwald its vitality. But not just yet. Many trials and adventures will shape Aidan into the man who can bring the kingdom back to its former glory.

From jonathan-rogers.com