The Castle of Chadwick

Ernie Chadwick is a bookish sixteen year old and not the adventurous type.  He was named after a 16th century uncle, King Ernest Chadwick.  Legend spoke that the King never really died after a gypsy foretold his doom.  A night of celebration ended with the King's youngest son murdering his elder brother, to claim the title as heir to the throne.  Hence!  The King vowed to live forever, thus denying his younger son the throne.
Whilst Chadwick sleeps in the sixteenth century, unaware to Ernie in the present world, he is the one born into the Chadwick bloodline with the flame-red hair.  Only he can turn back time and break the Chadwick curse as his destiny in life is to slay the dragon.  But the timid teen cannot kill a mouse, let alone a dragon.  Can Ernie reverse history?  And can one princess's love for him convince him to honor his duty to the Chadwick family, past and present?