The world is Rigantona. It's on a different Plane of Existence from our Earth – a rather better one because there the rules of magic work.
There is a Gate that links the two worlds, though they are many Planes apart. It operates randomly, when at all, and it's much easier to get there from here – usually by accident – than it is to get here from there. Thus most creatures found here – for instance humans – are also found there. But then there are the others...
Rigantona has two continents. On one is the Empire – ancient, mainly benevolent, wealthy. It serves the Gods of the Light. On the other continent are several kingdoms serving the Gods of the Dark Path, and these envy the Empire's wealth and distrust its motives.
Of course that means they invaded – a millennium ago. The invasion failed – mainly - beaten back by a great Emperor and powerful mages wielding Gifts from the Gods of Light. But now they are ready to try again. This time though they've prepared better. The Emperors have been replaced by a High Council: two key members have been suborned. The present wielders of the Gifts have been assassinated – and their deputies – now these powerful objects are in the hands of novices with precious little idea how to use them.
Clearly, the Alliance have got their preparations right this time and the Empire must be doomed. But there is a claimant to the old Imperial throne, an inexperienced but remarkable young woman. She has around her the brightest and best the religions of the Empire can offer. Furthermore, the Gods of the Light aren't happy about the death of the old Empire, and some of them are inclined to cheat...