NightWing-IceWing War
The dragon world of Pyrrhia was locked in a major war started by the NightWings "stealing" Prince Arctic over two thousand years before the events of The Dragonet Prophecy (Book). They had most of their battles in the Kingdom of the Sand. This event led to longstanding enmity between the NightWings and the IceWings, as seen when Morrowseer had the IceWing prisoners at Queen Scarlet's Palace all executed.
Background: Foeslayer and Arctic
Hope (Foeslayer) and Prince Arctic ran off together, which eventually led to this war.
Darkstalker
King Darkstalker's help was sought in this war, and he invented various magical superweapons for use against the IceWings.
Weapons
The IceWings developed several different weapons against the NightWings, including the Great Ice Cliff. The NightWings developed weapons of their own, such as a stick that, when broken, would kill all the IceWings.
Negotiation
Queen Vigilance and Queen Diamond sent each other angry letters under the guise of negotiation.
Resolution
The NightWings fled into hiding after Darkstalker's imprisonment without any true resolution to the war.