Into the darkness - Harry Turtledove

The death of a duke leads to bloody war, as the King of Algarve moves swiftly to reclaim the duchy which was lost during a previous conflict. But country after country is pulled into the war, as ancient alliances reassert themselves and a hatred of difference escalates into rabid nationalism.
Turtledove's characters are many and varied. From pompous kings to sly diplomats, from ordinary people - both men and women - caught up in the horrors of war to dragonfliers, they must all play their part in the battles which lay waste to country after country.
Harry Turtledove has created a fascinating world of various lands and peoples, of colour, high honour and the realities of bloody death. With echoes of the First World War, INTO THE DARKNESS is a tour de force of history and the utter futility of armed struggles between nations.