The Winner'sTrilogy by Marie Rutkoski

Set in a new world, The Winner’s Trilogy tells the star-crossed romance of Kestrel and Arin. It is a story of a warmongering empire, prison camps, spies, duels, rebellion, aristocrats living in luxury, ballroom dances, wicked rumors, dirty secrets, and games where everything is at stake, and the gamble is whether you will keep your head or lose your heart.