Lord of Forever by Mary Gillgannon

An ambitious English knight. A beautiful Welshwoman. A few fateful moments in a hidden forest glade spark a passionate love. But is it strong enough to survive violent rivalries, deadly politics and two cunning, scheming royals?
As the second son of a minor baron, English knight Nicholas Breutel will never inherit the family lands. But he vows to rise high and someday control a castle. His ambitions go awry when he captures a young Welsh warrior who turns out to be a beautiful woman.
Cristyn ferch Hywel is certain the terrifying knight looming over her intends to rape or murder her. She’s astonished when he treats her with courtesy and concern. And even more surprised by the sense of connection she feels growing between them.
Nicholas yearns to protect Cristyn, but as a knight in the garrison at Carwent Castle, there is little he can do but involve himself in the negotiations for her ransom. Then the Welsh double-cross the negotiators and Nicholas ends up a hostage himself.
While Nicholas languishes in a Welsh prison, Cristyn becomes a pawn in the plans of Llywelyn ap Ioworth, the most powerful prince in Wales. It will take the king’s degree, a violent battle, a risky escape and a desperate journey before the two lovers will have any hope of fulfilling their dreams and knowing a forever love.