Highland Lords of War and Thunder The Prequel by Donna Fletcher

Three legendary Highland warriors—Legion, Torden, and Creagan—have gone their separate ways, each carrying a reputation for extraordinary strength and skill. Their lives change when Queen Eudora of Morra Mist summons them because her throne is threatened and her kingdom is falling into unrest. Bound by an ancient debt owed to the queen's grandmother, the three warriors cannot refuse her call. They return to Morra Mist and receive three dangerous tasks that could determine the fate of the kingdom—and set the stage for the three romances that follow in the series.