Synopsis for To Betray My King (from Goodreads):
Would you choose to save your kingdom or follow your heart?
Brave and kindhearted, Arianna is a princess of a kingdom that nobody wants. The magicless. Marrying the charming, flirtatious, and egotistical Prince Roland was the last thing either of them wanted, but for the sake of their people they agreed. War breaks out with the neighboring kingdom, forcing the prince’s hand to join in the fight. He leaves his new wife with the only man he trusts, his childhood friend, a dutiful, strong, and handsome knight.