In a time not far removed from the awakening beneath the stars at Cuivienen, Vanophelion Carmegil and Brinaelinn Andaith were among the Sindar of the forests of Neldoreth and Region. As a swordsman Vanophelion was great among the march wardens of Elu Thingol, his weapon forged by the Dwarves of Belegost. Brinaelinn was an attendant of the court within the walls of Menegroth, and a weaver of high regard. Their love was great before first it was spoken, and in the years before the return of Morgoth, the two were married. In the first days of the long peace beginning in 260 FA, a child was born unto Brinaelinn and Vanophelion in the kingdom of Doriath. Her presence brought new light and hope to a land bathed in shadow, and for this she was named Sidhadel Eryndae, meaning "peace behind the forest shadow" in the Sindarin tongue.

As a child, Eryndae was happy, yet quiet. Her bright eyes studied the world around her, and sparkled at the beauty they beheld therein. While Vanophelion stood guard at the border of Melian's powers, the young elleth stayed in her mother's care at Menegroth. Here she gained an appreciation for all things beautiful of craft and construction, for surely Brinaelinn was among the most skilled of Doriath. The Lady Andaith's works showed both the history of Arda and the works of the Valar with sparkling intricacy, and she often wove ribbons for her daughter's hair when time allowed. Yet as great as Eryndae's appreciation for pleasures of the senses, she often stole away to the eaves of the forest to visit Vanophelion at his post.

When the coming of Men to Beleriand brought uneasiness to Doriath, so did Vanophelion worry and consent no more to his daughter's daily outings to the borders. Though half a century of age and of willful temperament, her father's wish Eryndae respected above all others, and thus was this request met with nary a complaint. She went back to the halls of Menegroth with Brinaelinn, there trying to hide her curiosity beneath the practice of fine arts. Over the next centuries she grew in grace and poise as well as years, spending more and more time in attendance of both the court and its guests. Already a refined lady in manner, Eryndae sought an apprenticeship beneath Orostaen, a young, newly-prosperous vintner and march warden beside Vanophelion.

But with the turn of the year to 455 FA came the Dagor Bragollach, and a turning point in Eryndae's life. Once more the brave march wardens set out to drive the darkness away from Doriath, Beleg Cuthalion their captain, and Vanophelion among their ranks. The battle was won, but Vanophelion Carmegil was among those fallen at the Pass of Teiglin. With hopes of easing the pain he knew Eryndae, whom he had begun to love, would suffer, Orostaen bore Vanophelion's long sword back to Doriath to give to her. Upon receipt of the news of Vanophelion's death, a cold light fell upon her bright eyes. She took her father's weapon in hand and, regarding Orostaen with not a word, retreated into the solitude of the forests to cry silent tears over the blood-stained sword. It was not until a month later that Eryndae returned to Menegroth. Where the sparkling garnet had fallen out of its place on the sword's hilt, a blue stone was embedded, and the sword was named Gwathoanir, meaning "stained with tears" in the language of the Elves of Beleriand. From then on, she wielded it as her own.

By the time of Thingol's death, much of Eryndae's passion and spirit was hidden, not to return for some time. In these uncertain years, she sought stability in a newfound loyalty to Silvarion, Lord of House Menelmen, during his years in Doriath following the fall of Nargothrond and the murder of Thingol. As Doriath fell to ruin in the 509th year of the sun, she saw the death of many she knew well, including her cousin Nenduien. Nenduien's husband Thileithel, Brinaelinn, and Eryndae were among the survivors who managed to flee with Elwing to the Mouth of Sirion. Later both mother and daughter sailed with Silvarion and the remaining membership of Nos Menelmen to the Isle of Balar; yet as the First Age drew to a close and Beleriand fell beneath the waves, Brinaelinn's weariness of Middle Earth became apparent. Thus was her decision made to journey into the Far West with the large host of Noldor and Sindar, while Eryndae chose rather to follow her allegiance to Silvarion and journey to Lindon.

There she remained for the extent of the age, seeming content to let rest her father's sword for a time, and with it, the fire upon her heart to thrive in battle. This change came to pass because in these years under the rule of Gil-galad, the elleth of Doriath was confronted with a face from her past in an unexpected reunion with Orostaen. She found healing of past suffering in their reconciliation, and much of the pensive chill in her stare was lifted. But his love was not meant to be professed, for with Orostaen among the ranks, Elrond Half-elven led an army over Ered Luin and into Eregion. Though left behind, Eryndae was not idle. In the less-frequented soils of Forlindon settled by those of nos Menelmen, the elleth cultivated the skill introduced to her in the earlier days of her friendship with Orostaen - winemaking. A love of all things celebratory was instilled in her by her mother, and so was this love stirred anew during these years. Among those of her skill Eryndae grew in prominence, want of her spirits extending at times as far as the Gray Havens.

In the later years of the age, her love of the fruits of the vine was retired as is necessary in times of war. Sidhadel Eryndae took up Gwathoanir, the blade of her departed father, for in the year 3429 SA Gil-galad and Elendil formed the Last Alliance of the Eldar and Edain. The great host amassed in Imladris for a time, and thus Eryndae began her search for word of Orostaen's fate. None was found, but the vintner and swordsman had no time for sorrow as the company marched to meet the Dark Lord's army. In a siege that lasted seven years, Eryndae fought tirelessly beneath the command of the brave Lords of the Eldar and Numenorians, and at the end of the age saw the slaying of both, as well as Sauron's fall.

Her loyalty stayed then with Silvarion in his return to the fair valley of Imladris with Elrond. There she now dwells, a long-time adherent to nos Menelmen, and a veteran warrior serving in the Tirith Imladhrim in order to lend her long-practiced skills to the protection of the valley. Yet by a lingering softness in her heart, Eryndae suffers not only the sword, but also walks the vineyards, offering her refined talent in winemaking as a gift to the inhabitants of Imladris. Though its extent is not shown as outwardly as with others, she takes great joy in sharing her expertise with other members of the guild of House and Fields. Herein she has been well-established, and thus offered the role of Miruvorthaer, Master Vintner.