Inda by Sherwood Smith (Inda Book 1) published by DAW is currently $1.99 in the US
https://store.kobobooks.com/en-us/ebook/inda
https://www.amazon.com/gp/product/B00256Z2DW
SYNOPSIS
Acclaimed Inda series within Sherwood Smith's epic fantasy Sartorias-deles universe • Military fantasy woven with courtly politics, vast worldbuilding, and diverse characters
Indevan-Dal is the second son of the Prince and Princess of Choraed Elgaer, destined to become his elder brother Tanrid's Shield Arm-his military champion. Like all second sons, he is to be privately trained at home by Tanrid, the brother whose lands he will one day protect.
When the King's Voice comes to summon Inda to the Military Academy, he might well feel foreboding, or even fear-war is imminent-yet youthful Inda feels only excitement. But there are things that Tanrid hadn't prepared him for, and Inda will soon learn that the greatest threats to his safety will not come from foreign enemies, but from supposed allies within his own country.