Firesong by William Nicholson

The Manth people are at last free to seek their promised land, led by Bowman and Kestrel's mother, a prophetess. But the journey is long and hard, filled with many dangers, enemies, distractions, and temptations. And each of the travelers is preoccupied with his or her own worries. Bowman is torn between his attraction to Sisi, a former princess, and what he believes is his destiny-to sacrifice himself for the good of the people. Kestrel also feels a pull toward a mission, toward something-but for some reason, she cannot envision her life beyond the journey.