Young Hawks Flying — Toni V. Sweeney

With the death of their parents in the Genocide Wars, the orphaned sons of Riven kan Ingan and his beloved Barbara flee to separate countries to escape the margrave's injustice.
Eldest son Val rides north to Ghermia, his mother's country, where he's taken in by a band of barbarian marauders as ruthless as he.
Ilke the Priest and nine-year-old Merigan turn their horses' south, seeking sanctuary among the tribes in the Assamedean desert.
Twins Hroric and Shael go to the far eastern kingdom of Chalêit, where their reckless natures enable them to become accomplished thieves.
All agree to return and help Val avenge their parents, but none believe that will happen. Until it does… adventure, danger, death, and love await Riven's five sons as they grow to adulthood and gain the strength to exact their revenge upon the insane margrave of Francovia.