Mage's Blood. The Moontide Quartet Book 1

The Moontide is coming. Urte stands on the brink of war. Now three seemingly ordinary people will decide the fate of the world. Urte is divided, its two continents separated by impassable seas. But once every twelve years, the Moontide sees the waters sink to their lowest point and the Leviathan Bridge is revealed, linking east to west for twenty-four short months. The Rondian emperor, overlord of the west, is hell-bent on ruling both continents, and for the last two Moontides he has led armies of battle-magi across the bridge on crusades of conquest, pillaging his way across Antiopa.
But the people of the east have been preparing - and, this time, they are ready for a fight. An epic fantasy, rich in intricate plots, intrigue and treachery. Vast forces collide and ordinary people make heart-rending choices that will shake the world.'A complex world populated by a rich and diverse cast of characters .