Saxon Blade Norman Blood by Virginie Marconato

1086. Twenty years after the battle of Hastings.

In a country in turmoil, Rowena is asked by her mother to kill William de la Falaise, the Norman baron responsible for the killing of Godric, her stepfather. When she finally finds herself in a position to do so, Rowena realizes that William is not quite the ruthless brute she imagined. To her dismay, she finds it impossible to fulfil her mission and remain unaffected by his masculine charm.
William, for his part, cannot deny the attraction he feels for the mysterious Saxon. Despite his better judgement he is drawn to this girl who could prove his downfall. He cannot afford to trust her, but he will have to keep her close.
In his bed, if need be.