Sisterhood of Elune

The Sisterhood of Elune (aka Sisters of Elune or simply the Sisters) could be the oldest night elf religious and magical order, predating the quel'dorei by some 2,000 years. As the name implies, they are an order of priestesses dedicated to the worship and servitude of the moon goddess, Elune. The Sisterhood is led by the High Priestess of Elune, Tyrande Whisperwind, while the priestesses of Elune are the elite of the organization.

They have existed long before the Great Sundering, and formal worship dates back about 15,000 years.

War of the Ancients
The headquarters of the Sisterhood was originally the Temple of Elune in the city of Suramar, but the Sisters staffed temples and chapterhouses on the whole length and breath of Ancient Kalimdor. The temple was lost when Suramar was overrun by the nathrezim, but the Sisterhood, under the leadership of high priestess Dejahna, escaped and flocked to the banner of Lord Ravencrest in the Kaldorei Resistance. A few weeks after the abandoning of Suramar, Tyrande Whisperwind was made high priestess following the death of her predecessor at the hands of Hakkar the Houndmaster. The Sisterhood continued to fight in the War of the Ancients after Tyrande's capture by Xavius — under the leadership of first Marinda, and then Maiev Shadowsong.

The first members of the Watchers and the Sentinels were from the Sisterhood of Elune.

The Long Vigil and current times
Following the conclusion of the war and the creation of Nordrassil, the Sisterhood continued in a less formal role (many of the Sisters became Sentinels), particularly during the Long Vigil. After the defeat of Archimonde at Mount Hyjal and the night elves freedom from the Long Vigil, Tyrande led a much more formal and religious Sisterhood of Elune from the Temple of the Moon in Darnassus.

The Sisterhood helped the troubled citizens of Auberdine.

During the War Against the Nightmare, Shandris Feathermoon commanded the Sentinels and the Sisters of Elune to help the inhabitants of the ruined Darnassus. Tyrande would later send some of the Sisters into Alliance-held lands in order to help their people recover from the terrible ordeals of the Nightmare. The priestesses of Elune were also the ones responsible for preserving Malfurion's slumbering body and keeping him alive even as unbeknownst to them, Fandral Staghelm sought to slowly poison him to death.

A branch of the Sisterhood of Elune, implied to be an ancient offshoot of the Suramar priesthood in Val'sharah, was apparently given the Tears of Elune after Elisande and her Highborne used the Pillars of Creation to seal the Legion's portal, and shortly before the Great Sundering and the isolation of Suramar. Lyanis Moonfall stated that her "order" has protected the sacred artifact at the Temple of Elune for thousands of years. Tyrande Whisperwind reunited with these priestesses ten millennia later and together, they successfully defended the Temple and slew the corrupted Ysera, whereupon Elune directly intervened to purify the fallen Aspect as well as her Tears.

Battle for Azeroth
After Sargeras destroyed Silithus, Tyrande sent several priestesses there. Together with the druids of the Cenarion Circle, they built moonwells there.

The Sisterhood of Elune attempted to aid Malfurion Stormrage and their kin in Darkshore during the War of the Thorns, with some priestesses rallied to the region to bolster the other kaldorei forces. Most of the Sisterhood of Elune, including Astarii Starseeker, apparently perished in the Burning of Teldrassil after refusing to abandon the remaining night elves in Darnassus. However, those who survived fought in Darkshore against the Horde forces immediately after Teldrassil's destruction, many having apparently lost their families, and enchanted Lunar Wards to assist their defenders, only to be slain by the Horde. Moon Priestess Maestra was targeted by the Horde in Ashenvale at Maestra's Post, controlling the pass between Ashenvale and Darkshore. Several Devout Priestesses were slain in Nazmir during the Faction Assaults when the Horde blighted their ancients.

Despite their heavy losses and the destruction of Darnassus and their Temple of the Moon, some members of the Sisterhood, including Moon Priestess Lasara and several Nightwreathed Priestesses would join the Battle for Darkshore in revenge for the Burning of Teldrassil, being infused with Elune and Tyrande Whisperwind's power, and ultimately survived the Fourth War, witnessing Tyrande's victory speech at Bashal'Aran after the Alliance successfully reclaimed Darkshore.

Role in the night elven society
The Sisters are a major and active night elven political faction, and fulfill the role of magistrates, officials, and others for the night elven government. The highest-ranking of the Sisters are privy to the government's most important secrets, such as the original condition of Malfurion Stormrage and the power struggle that erupted between Tyrande Whisperwind and Fandral Staghelm.

The Sisterhood of Elune is the highest echelon of the priesthood that serves the goddess of the moon, Elune. The Sisterhood has remained exclusively female up until recent times. This is largely because of a common belief that the deepest mysteries of Elune can only be comprehended by women. Although the vast majority of Elune's priesthood is still comprised of night elven women, the order has come to accept Kaldorei males into its ranks as well.

The Sisterhood has maintained its role since the days of the ancient Kaldorei Empire, over 10,000 years prior; although this role was significantly less political before the Great Sundering. Owing to their military capabilities, the Sisterhood also played an active role in the War of the Ancients, where they joined with the Kaldorei Resistance to curb the invasion of the Burning Legion. They ultimately played a decisive role in numerous battles with the demons, acting as both, elite shock troops, and adept healers.

Membership
All priests who served Elune were night elf women. However, after the devastation of the Third War, they thought that the organization had drifted too far away from night elf society and decided to open up their group more to the world. As a result, although a majority of Elune's priests are still women, the order now welcomes men into its ranks.

Elune expected dedication from her priests, but she did not demand that they give her every waking moment — the Mother Moon was a kind, loving mistress. One of these dedications was called the Ritual of the High Moon.

The center of her worship was the Temple of the Moon in Darnassus. Tyrande Whisperwind is her high priestess, but many priests, are found throughout the world, ready to heal the war-weary Azeroth with her light.

Notes and trivia

 * The Warcraft Encyclopedia says that since the night elves emerged from their societal isolation, the priests of Elune have also extended membership to a few priests, male and female, of other races. No priests of the moon from other races have been seen.
 * The Sisterhood have a special language to commune with the lunar deity.
 * The server Sisters of Elune US is named after the organization.

Speculation

 * Judging by the appearances of Priest Ellandras, Priest Iridil, and Priest Sal'shanan, they may be one of the first known male members of the organization.
 * The Disciples of Elune in Sargeron were likely priestesses of the Sisterhood.