[1] The Shi'ar are cold-blooded[2] humanoids of avian descent; they resemble humans with feathered crests atop their heads in lieu of hair.
[3] Internally, they have lightweight and hollow bones, and on their forearms there are still some vestigial feathers left of wings that were lost over millions of years of evolution.
Its central base of power is located on the "throneworld" Chandilar, while the Shi'ar homeworld is called Aerie (it is unknown if the planet still exists).
The leader of the empire is given the title Majestor (male) or Majestrix (female) and is a hereditary position, occupied by members of the royal family of the Shi'ar.
However, in practice, the head of the council (the Majestor or Majestrix) exercises strong executive control and can institute policy virtually by decree.
Just to name a few, Empress Lilandra Neramani tried to broker peace between the Kree Empire and the Skrull Empire to help bring an end to their devastating war: she sought interstellar accord when deciding how to end the threat of Dark Phoenix, and attempted to avenge the destruction of Tarnax IV, the Skrull throneworld, by Galactus.
[37][38] After leaving their world, the Shi'ar started an intergalactic Empire and forced other cultures in order to become stronger and ruled for millions of years.
[42] In the 1980s, Lilandra and D'Ken's unstable exiled elder sibling Deathbird made several attempts to overthrow her sister from power.
[46][47] Professor X's evil twin sister Cassandra Nova single-handedly destroys a good portion of the Shi'ar Empire.
Inhabiting the body of her brother, Nova asserts control of Empress Lilandra and causes a Shi'ar civil war.
[48] Despite the aid she gave them by eliminating the threat of Cassandra Nova, the Shi'ar still held a grudge against Jean Grey for the destruction she caused as Dark Phoenix.
The Shi'ar Death Commandos murdered Jean Grey's father, niece, nephew, and other relatives in an alien invasion on Earth, thus inciting the wrath of Rachel Summers, the daughter of Jean Grey and Scott Summers from an alternate future, who has since declared vengeance on the entire Shi'ar Empire.
Vulcan and Gladiator (still the praetor of his Imperial Guard) attack the leader of the Scy'ar Tal and are easily defeated, whereupon they retreat deeper into Shi'ar space.
Early in their history, the Shi'ar attacked them, killed a great number of their people, making the rest flee for their lives.
The Avengers were ready to meet their end, but the Illuminati intervened used the controller disk of a rogue planet that shared the same space with Earth, while Iron Man flew to the Sol's Hammer, and used it, successfully destroying the Shi'ar fleet, including the Imperial Guards.
[64] In the Natural Disasters Round, Sharra and K'ythri use their power to cause a tidal wave in order to ferment greater worship in the survivors.
Greatly angered at such a turn of events Sharra and K'ythri order their Majestor to eviscerate her homeworld in retribution; but the Emperor of the Shi'ar rebel's against their gods after their wanton display.
[66] In their final fit of mindless ire, the Shi'ar gods summoned the Phoenix Force to eviscerate the galaxy spiting everyone who defied them.
Later after a sorrowing battle following the appeasement of the Phoenix, the former gods of the empire are taken away to the dungeons of Omnipotence City for their crimes and reckless actions.
[67] During the search of the Infinity Stones, Razor reveals the true origin of the Tree of Shadows and the creation of the Fraternity of Raptors, according to Razor the Tree of Shadows was created eons ago by the Elder of the Universe known as The Gardener who tried to bring life to the Null Space and planted it in the Darkforce Dimension.
Eventually, Null Space and the Tree of Shadows were discovered by a more pre-historic version of the Shi'ar and the Skrulls, a find that ended in war erupting between the two alien races.
It can be assumed that due to the incident with Rook'shir, the Shi'ar then intended to use the seeds of the Tree of Shadows to create an army to unleash Ratha'kon or the Dark Starhawk, a being who would be able to contain and act as a "predator" to the Phoenix Force, however, while the Fraternity of Raptors attempted to mimic the Cosmic entity, because of their mechanoid nature, they were unable to unlock much less ascertain the coveted true power of which within their ranks.
Sought to utilize the amulet of Christopher Powell as the conduit in which Talon-R would become host to the Dark Starhawk with intent to raze the planet Earth, but was destroyed by the possessed entity due to his reviled nature as a result.
[71] To actualize their claim, the insurgents are in hot pursuit of an item pertaining critical importance to the Shi'ar Imperium, a glowing egg contain the next successor to monarchy and the throne.
The Marauders and Xandra come into conflict with the Shi'ar's sect of secret-keepers the Crimson Kin, who eventually assassinate her to stop her from "betraying" their darkest secrets to Krakoa.
[73] Eventually, Kate Pryde and her band of Marauders discover the greatest secret of the Shi'ar - an encounter with the inhabitants of Earth that occurred billions of years ago.
The ancient Shi'ar, still possessing their avian traits, were a race of raiders allied with the Lupak, and on Earth they discovered a civilization capable of repelling them, a mutant society named Threshold.
Their beliefs state that all of the Earth was originally a prison created by ancient alien civilizations to hold the Phoenix, but its presence at the core led to the creation of life on Earth, and the Phoenix's direct influence resulted in all major steps of evolution for man, and specifically, led to the creation of mutants.
Ultimate Lilandra is not an alien, but the Majestrix of the Church of Shi'ar Enlightenment, and contacts Professor Xavier with the offer of funding his school's immense budget, in exchange for the chance to see if Jean Grey is the human host for The Phoenix.
[142] In Marvel Zombies Return, led by Luke Cage of another reality, the Shi'ar were defeated and killed by the zombified heroes of the Earth.