The Peril of Rast by Christopher Hoare

Imagine the worst possible time, the interregnum while rebelling magic forces slowly kill the reigning Drogar. Prince Egon has to take up the succession as the new sorcerer-king of Rast, and admit the deadly magic into himself in a way he can control.

Yet the Offrangs arrive on the coast, imperialists whose power comes from steam and iron, and who disbelieve in magic. Commander Antar seeks to conquer Rast. Egon has no time for caution, he must act at once.

He also has to rescue Jady, the last of the Soulingas, Guardian of the Silent Forest, from the evil Deepning Pools whose resurgence she has thwarted. Even more troubling, he must send his sweetheart away, for she is not from the magic lineage who can bear him an heir. She goes to meet the Princess destined to supplant her, with anger in her heart.

The oracle given by the Pythian, living beneath the Palace of Rast, predicts the crisis can only be resolved by everyone’s efforts – even the actions of enemies – until the Prince is established securely and able to turn the magic’s fury upon itself.