The Left-handed Warrior — Barbara G. Tarn

The struggle between Humans and Genn gets vicious.
Orphaned by Human bandits, adopted by Genn, seeking revenge and becoming a warrior under a not-so-accomodating Emperor. Especially if you refuse to serve him to side with the Genn.

Welcome to Silvery Earth. Water beings, winged people, shape-shifting dragons and elf-like beings mingle with humans throughout the history of this world.