Traitors of the Black Crown by Cate Pearce

Goodreads Storygraph

"Three women will betray the black crown. A Knight. A Duchess. A Queen. Raena Schinen narrowly escaped when the Queen’s guard murdered her entire family. If Raena’s survival is exposed, she’ll be next. For fifteen years Raena has hidden as a male Knight, “Sir Rowan”, consumed by her vengeful desire to assassinate the Queen. The moment Raena is close enough to exact her revenge, she is unexpectedly exiled to a foreign land. There she serves the common-born Duchess Aven Colby, whose suspicious kinship with the Queen further threatens Raena’s delicate secrets. Just as they become united in a common goal to curb a looming invasion, unexpected heat and romance blossoms between “Sir Rowan” and Aven. The peril demands they set out on a journey to form clandestine political alliances, risking the Queen’s wrath, and drawing Raena and Aven closer together. But no one in the kingdom could have imagined the sinister foe rising from below the surface. In order to save themselves and those they love, Raena, Aven, and the Queen must recognize who are the oppressors and who will unite against the Black Crown."