King Edward of England looks to secure his annexation of Wales and resolves to put the heir to Gwynedd's throne, the orphaned infant Princess, Gwenllian, out of mind, secure and forgotten in a Lincolnshire Priory. The lady Rowena, ever loyal, undergoes many an ordeal to find, comfort and protect the miserable child, whose real identity has been cruelly kept from her.

Eighteen years later when the King conceives a plan to settle any question of Welsh succession and news of the Princess leaks to those who would free her, Rowena finds herself faced with the most agonising of choices.