Glie is 5706 years old at the end of the Haibane Renmei series, its concept dominated by author Yoshitoshi ABe, with significant contributions from Matthew Costello, brought together and enhanced by Terry Wilson, who believes it might have something to do with Revelation 21
Glie begins as a gathering of the survivors of the ancients on Mars in 2344BCE. The First War was in progress at the time. The ancient society of angels (featherwing beings, 羽音) with large flying wings arose on the outer of the two fertile planets in our solar system. Earth had only humans. Featherwings could become human by losing their wings, and by the time of the First War, most of them had. Both fertile planets suffered disasters in 2344BCE, with Mars being destroyed and Earth nearly so (Genesis 6-9). The First War occurred when the forces of hell invaded from their realm into ours by means of the ancients' unitary teleporters. The survivors gathered and constructed quantum particle teleporters, and created an incredibly dense six liter object with the bodies and souls of 144,000 people, including 4512 featherwings into a group called the Praeleanthor, in an object later known as the Kikotsu no Rittae (気骨の立体, Soul Cube, see also Doom Wiki), but at this time, had no name, even though it gets many later. It is given to featherwing warrior Grimm Rieper. After three years of fighting, Rieper succeeds in destroying all of the ancient teleporters except for one prototype, which is stolen away into the intermediate dimension informally known as "hell". The final remaining teleporter is destroyed as it teleports a handful of survivors to Earth across interplanetary space, founding the secretive Featherwing Brotherhood, which, by means of the wings' blessings to remain secret, promptly forget their origins and eek through history until 15 November 2145.
Humanity discovers the Kikotsu no Rittae during their exploration of Mars in 2104, whence it pretends to be an ordinary object, but with little success. Archaeologists and physicists sponsored by the Union Aerospace Corporation are unable to measure its most basic characteristics, and the Praeleanthor do a poor job of faking them. The object's true mass, despite its small size, is about eight thousand tonnes, on the same order as an oceangoing missile cruiser. The Union Aerospace Corporation unwisely recreates the ancients' teleporter technology, and the demons imprisoned in the intermediate dimension begin to emerge by taking over humans sent through, using them as hosts, most successfully Malcolm Betruger, hosting a demon named Maledict. Maledict's power is great enough to capture the Soul Cube, and forces it into the intermediate dimension on 15 November 2145. With the only entity that can stop them safely imprisoned in hell, enemy forces invade the base on Mars, just after the arrival of Devon Greenborough, codenamed Tatakai, secretly sent by the Featherwing Brotherhood as the angelic counterpart to the creatures of evil which inhabit the intermediate dimension. There she marries and transforms Jack Campbell in a ceremony presided over by the Praeleanthor, who are exceedingly happy that their flying wings have not gone extinct. The pair form Operation Tatakai, to lead human and featherwing kinds against the enemy in the Final War, an eleven year conflict that ends with Jack Campbell's death on 18 November 2156, his wife shot out of the sky only three days earlier.
The Kikotsu no Rittai leaves Tatakai on 1 November 2156 to search for a site to Deploy, and on 16 November, find one near Chita, Russia, by then a burnt-out ruin. There they found Deployment (配備, Haibi), a city design that the Praeleanthor have been working on for thousands of years. Since their wielders called themselves by the Japanese word for Battle, they select this as their official language. The first, and most important structure of this city is a 100m tall circular wall made in one piece of stone forged from the local bedrock. It is so large that it has a moat entirely enclosed by the wall structure. The foundation runs deep and encloses the entire basin-like city. It is called Haibi. The 4512 featherwing beings in the Praeleanthor are unable to emerge in their flying form because the "magical" nature of the wings can't be recreated by the quantum particle teleporters. Even their highly varied colors are lost, replaced by a spectrum of greys ranging from black-tipped pigeon grey to a dove-like white, reflecting the health of the wings themselves. The featherwings lose all reproductive ability, as well as the ability to fly, the secret poison they use to defend themselves is replaced by a conspicuous forged halo that glows in the dark. Far from celebrating their new city, the Praeleanthor mourn the sad state of their former featherwings, now called ashfeathers (灰羽, haibane).
The above paragraph forms the subject of the Kikotsu no Haibi video at Metacafe:
The special characteristics of the ashfeathers (cocoons, dreams, leaving the nest in light shows) soon emerge, painting a happier picture for these new beings. Toga are a self-regulated bin of Fallen ashfeathers and Saved hellspawn, forming an ambiguous neutrality between the evil that has taken over the Earth, and the tiny remnant of human and haibane enduring behind their mighty wall in Haibi. The uneasy peace ends on 21 December 2232, 76 years into Haibi's existence. These complicated events are the subject of the second fanfiction novel by Terry Wilson (user fhd_remix): FHD Remix: The Battle of Haibi. The battle ends with the emergence of a mysterious light that rebuilds the wall and protects the interior from all incursions, especially from the air. On the Saturday after the winter solstice, this light can always be observed, along with the voices of the Praeleanthor's children happily singing. At least that's the experience inside the wall.
Glie emerges from this second apocalypse as a stalwart, if forgetful band of survivors who rebuild the river's dyke and patiently wait for the floodplain to dry while huddled in the one remaining Defense Tower, of the original six. Finally, when able to do so, they rebuild their city and reinhabit the surviving buildings outlying the buried ruin. The ashfeathers, responsible for the defense of Haibi and therefore its destruction, are made into a second class and restrained by quaint rules. 1260 years after Deployment, a blonde haibane woman emerges from her cocoon, and, remembering how she was blown out of the air while defending the last scraps of humanity, names herself Battle (Tatakai, 闘い)...