Historical background
While the Firanyan Harpies of the Harpy Hills have seen numerous Queendoms, there has only ever been one Queendom for the Siadúnan Harpies in Far Salahad: the Siadanlén Queendom. This Queendom, established by Ištara Ivoryfeather in the early 800s AA, unified the Siadúnan Harpies and forged from them a realm which stretched from Azka-Sur in the west and covered large parts of Rahen in the east. It maintained a light touch with its subjects and tributaries, allowing it to persist for some two centuries. It might well have lasted longer, if not for the arrival of the Phoenix Legions.
Though Siadanlén was shattered by Jaher's Legions, the Siadúnan Harpies were not truly conquered by the Phoenix Empire. It is, after all, rather difficult to subjugate a race which lives atop mountaintops and can simply fly away from would-be administrators.
However, though the Harpies remained independent from the Phoenix Empire - even though Elven maps might say otherwise - the Siadanlén Queendom would not return, for the Siadanlén Queen and her designated heir had both fallen trying to fight off the Elven Legions and in the ensuing succession crisis, the Siadúnan harpies fractured into many matriarchies and flocks.
Today, only three Matriarchies worth the name remain: Siadán, Mulén, and Elaiénna, which have been locked into an uneasy balance for about a century and a half, since neither could hope to take on the other two and still prevail. Of course, some matriarchs still tried to do so, with the second-to-latest attempt being the Muléni matriarch who ruled about 40 years ago.
She launched an offensive and managed to seize large swaths of Siádan lands and even held on to it for several years, but was defeated when Elaiénne entered the war on Siadán's side.
The latest attempt at unifying the Matriarchies? That was some 10 years ago, when Elaiénna attacked Siadán.
A Sister's Overreach
This offensive was spearheaded by Jasiéne's sister, Iára heir to Elaiënne and the most gifted military mind for generations. For years, she had been drilling Elaiénna's forces and taking them on raids, to build up a force that would let her realize her ambition: to subjugate the other Siadúnan Harpies and elevate Elaiénna from a Matriarch to a Queendom. At the time, the matriarch's health was ailing and Iára was already matriarch in all but name.
However, her ambitious nature meant that she would not be content to simply be crowned as the Matriarch of Elaiénne when her mother died. No, she wanted to crown herself as the new Queen of all Siadúnan Harpies, and for that, she would need to seize the Crest of Ištara from Siádan.
The Crest of Ištara was a gem-adorned golden crown created by the very first Queen of Siadúnan, and ever since its creation, Queens of Siadúnan and subsequently Matriarchs of Siáden have added their feathers to the Crown on their ascension, creating a fabulous rainbow trail, which spoke to the long and storied lineage they could lay claim to.
To seize the Crest of Ištara and start her conquests, Iára launched an attack on Siádan and achieved several minor victories over Siádan in the first few months of the war, and launched a successful raid against Siadúnaiún, where she managed to seize the Crest of Ištara. High off her victory and preoccupied with dreams of her impending coronation, Iára was overconfident and distracted, and fell for a trap laid by the Siadán matriarch.
While Iára escaped with her life and the Crest of Ištara, half her forces were slain.
It was fitting, then, that the conclusion of the war would see Elaiénne lose half of its territory, but such an outcome would have been seen as a miracle in the aftermath of said battle, as the Siádan army was bearing down on Larfíra.
Rise to Power
There, a single Harpy flew out to meet them: Jasiéne.
Unlike her sister, Jasiéne had no skill at commanding armies, nor could she wield magic to smite down the approaching Siádan army. She did not even come bearing arms, having only one thing in her hands: the Crest of Ištara, which she had taken from her sister while Iára was sleeping. Guards had been posted to keep the Crest safe, naturally, but Jasiéne needed naught but a few minutes to convince them that Iára had failed Elaiénne and that if they did not help her, Larfíra would be overrun in a matter of days.
Jasiéne was swiftly accosted by Siádan warriors, with whom she smiled and joked as if they were the best of friends, before asking if they could help her return the Crest to its rightful owner.
Suspicious of trickery, Jasiéne's wings were bound and she was brought to the Matriarch Astárta of Siádan. Here, Jasíene asked - nay, pleaded - for permission to return the Crest, apologized most profusely for Iára's actions, and then explained that with her mother's ill health and her sister's disgrace, Jasiéne had been proclaimed as the new heir, has been given the Crest, and has then been sent to negotiate a cessation of hostilities.
When Astárta archly asked why she would accept a negotiated surrender rather than seizing all of Elaiénna by spearpoint, Jasiéne laughed mirthfully, bowing her head to the matriarch in a show of slight submission, and politely requested that she not be treated like a child. After all, while she was not yet the matriarch and did not yet grasp the many intricacies of rulership and politics, even she knew that an assault on Larfíra would be a bloody and drawn-out affair and that even if Astárta managed to seize the city before Múlen took advantage of the distraction and began besieging the Siádun capital, the Elaiénni army was still strong enough to inflict significant casualties from a fortified position.
Which would, Jasiéne concluded off-handedly, lead to Mulén trying to finish what they started 50 years ago, since Siádan would be weakened from the assault and this time, there would be no Elaiénne to act as a counterweight to Múlen. Then she tilted her head as she peered at the Crest of Ištara, shook her head, and apologized for her inattentiveness. She was, she explained, just trying to remember what colour the feathers of the Muléni matriarch had, as she was trying to picture a world where Siáden did press the attack.
It was hardly the height of subtlety, but the thought was alarming enough to Matriarch Astárta that she eventually agreed to end the war, though not even Jasiéne's silver tongue could have ended the war without concessions, leading to Elaiénne losing half its territory... as well as Iára being handed over to Siádan.
When Jasiéne returned to Larfíra with news of her deeds, she was hailed as a hero despite the territorial losses.
Iára, naturally, vigorously protested the peace treaty and tried to mount a coup. Before the war, the army was loyal enough that she would have had no trouble seizing power. After the disastrous battle, however, her forces had lost confidence in her, and aside from a small group of hardcore loyalists who were quickly overwhelmed, the Elaiénni army stood with Jasiéne.
Thus, Iára was handed over to Siáden and would eventually be publicly executed in Siadúnaiún, while Jasiéne was proclaimed the new heir.
The Union
Mere months later, Jasiéne became Matriarch at the age of 34 after the death of her mother, but while Elaiénna had survived, the Matriarchy had been weakened, to the point where if a conflict between Mulén and Siáden erupted and either side got the upper hand, the support of Elaiénne might not be enough to tip the scales.
And so, she looked beyond Siadúnan, and to the Elves which had shattered the Queendom. For some time now, there had been an agreement between the Sun Elven Desert Legion and Elaiénne, where the latter would provide food and water in exchange for mates. It had been a profitable agreement, but previous Matriarchs had been hesitant to expand the partnership. Not only did the Sun Elves have an annoying tendency to prattle on about Light and Darkness and how their leader was Chosen by a dead Bulwari God to save the world, but many harpies - even in Elaiénna - resented the Sun Elves for ending what was perceived as the golden age for Siadúnan Harpies.
Given the weakened state of her realm, Jasiéne travelled to the camp of the Desert Legion, hoping to secure promises of military aid, training, or equipment, so that Elaiénna could gather the strength they needed to prevent Mulén and Siádan from conquering the other. Maybe even an outright military alliance.
She found all that... and so much more.
Once Jaddar and Jasiéne sat down to talk, they found much potential gain from cooperating. The Jaddari would provide bows and training in the art of archery to Elaiénne, in exchange for Harpy scouts being attached to the Desert Legion to spot foes, friends, or oases in the vast Salahad Desert, just to start with. More supplies would be provided to the Desert Legion while promising Harpy Mages could study under experienced mages. On and on the two spoke, each growing more invested in the potential partnership with every minute.
If not for the fact that the two immensely enjoyed each others' company, a treaty would likely have been signed within an hour or two of the negotiations starting. Instead, they spoke well into the night, conversation flittering effortlessly from topic to topic. From hobbies to politics to dreams and hopes to religion.
And when Jaddar spoke of religion, of the truths and revelations bestowed upon him as he was meditating atop the Mountain of Clear Sight, of his vision for a world where anyone - regardless of race, background, or birthplace - can take up the Fight against the Darkness and become a Chosen, Jasiéne listened intently... and was convinced, declaring that she, too, would become a Chosen, and would join the Fight.
Since then, Elaiénne and the Jaddari - and Jasiéne and Jaddar - have only grown closer, and with every day that passes, more and more harpies within Elaiénna abandon their old ways in favour of the Jadd.
This union of nations is best exemplified by Jasiéne's only daughter: Jaddarésa, a literal union between the two rulers. Though still a child, she shows great promise, being blessed with not just her mother's diplomatic prowess or her father's military mind, but also possessing potent magical powers.