It is 1109 and the Welsh warrior and firebrand, Owain ap Cadwgan abducts Princess Nest from the castle she shares with her children and her husband, Gerald of Windsor. King Henry of England, furious that Nest, who is also his lover and mother of his son, begins a manhunt to find Owain and return Nest to her husband. In Gwynydd Gruffydd ap Cynan and his wife risk everything to hide them and get them to safety in Ireland despite the efforts of Gronwy ap Owain, Angharad's vicious brother who would like to see Gruffydd and Owain dead.

King Henry uses Bishop Richard to start kinship warfare in Wales. Madog ap Ithel is the Bishop's pawn and kills both Owain ap Cadwgan's father and Uncle. Another of Owain's uncles, Maredudd pleads with the king for Owain's return and is successful but Owain continues to harass the Normans as does Gronwy in the North. Finally, Henry declares war against the Welsh determining to exterminate them all. As the Welsh hide in the mountains away from the Norman invasion Owain learns from his scheming Uncle Maredudd that Gwenllian has formed an alliance of her own with Griffith ap Rhys, his old lover Nest's brother. Owain turns traitor and Gronwy moves in ready to be the new king of Gwynedd. Can Gruffydd and his family survive the greatest army ever led against Wales?