Nymeria's War

"My ancestor, Mors Martell, saw her and desired her; and proved that where armies failed a tongue may succeed. Wedding his strength to hers, his spear to her sun, they subdued all his rivals together."

- Prince Oberyn Martell

Nymeria's War was a a war waged between House Martell along with the Rhoynar immigrants led by Nymeria and the independent houses of Dorne. It resulted in the victory of House Martell and the unification of Dorne under their rule.

Aftermath
House Martell adopted the title of Prince of Dorne, following the tradition of the Rhoynar people. They also combined the Martell sigil, a spear, with Nymeria's emblem, a red sun, resulting in the modern heraldry of House Martell.

As the local Dornish population intermingled with the Rhoynish immigrants, a number of traditions were adopted, among them equal primogeniture, thus allowing women to rule in their own right and even carry on the family name.

In the books
In the A Song of Ice and Fire novels, little is revealed about Nymeria's War. The World of Ice and Fire expands on the history of the Martell conquest of Dorne. Mors Martell was crowned Prince of Dorne by Nymeria before the unification was complete. The Martells defeated and gained the support of Houses Dayne, Uller, Toland, and Fowler, but contended with the powerful House Yronwood and their vassals: Houses Blackmont, Jordayne, Qorgyle, and Wyl. Prince Mors perished in the Third Battle of the Boneway, slain by King Yorick V Yronwood, self-fashioned King of the Dornish. Nymeria, however, carried on the war and defeated Yorick two years later.

After her victory, Nymeria sent six defeated kings to the Wall: Yorick V Yronwood, Vorian Dayne, Garrison Fowler, Lucifer Dryland, Benedict Blackmont, and Albin Manwoody.