The False Prince (The Ascendance Trilogy #1) by Jennifer A. Nelson

Goodreads Synopsis
The False Prince is the thrilling first book in a brand-new trilogy filled with danger and deceit and hidden identities that will have readers rushing breathlessly to the end.

In a discontent kingdom, civil war is brewing. To unify the divided people, Conner, a nobleman of the court, devises a cunning plan to find an impersonator of the king's long-lost son and install him as a puppet prince. Four orphans are recruited to compete for the role, including a defiant boy named Sage. Sage knows that Conner's motives are more than questionable, yet his life balances on a sword's point -- he must be chosen to play the prince or he will certainly be killed. But Sage's rivals have their own agendas as well.

As Sage moves from a rundown orphanage to Conner's sumptuous palace, layer upon layer of treachery and deceit unfold, until finally, a truth is revealed that, in the end, may very well prove more dangerous than all of the lies taken together.

An extraordinary adventure filled with danger and action, lies and deadly truths that will have readers clinging to the edge of their seats.