[1][2] There are eight books in this series: The Forests of Silence, The Lake of Tears, City of the Rats, The Shifting Sands, Dread Mountain, The Maze of the Beast, The Valley of the Lost and Return to Del in that order.
The main story arc takes place during a time of economic depression and political repression, under the dictatorship of the evil Shadow Lord.
Eventually, the Shadow Lord also managed to corrupt the trade system, sever communication between major cities, and render civilians politically powerless.
Wanting the Shadow Lord overthrown, Lief leaves home to search for the seven gems: the topaz, the ruby, the opal, the lapis lazuli, the emerald, the amethyst and the diamond, which represent each of the ancient tribes of Deltora.
The book is split in two parts, the first, acting like a long prologue, following the lives of Jarred and King Endon, of their childhood and adult life up to when the Shadow Lord conquers the land of Deltora and the gems are separated from the Belt.
Jarred watched the palace every night for the next few years, until Endon signaled him and by then it was too late to save the gems and prevent the Shadow Lord's invasion.