The Skrulls were born from their homeworld Skrullos within the Andromeda Galaxy, but they have found their way to many parts of the known universe.
Skrulls are a Reptilian-Humanoid race, most are physically malleable, able to alter their shape, size, and/or color at will. Skrull females lay eggs like Earth reptiles but have mammary glands and nurse their young like Earth mammals.
- Note, the Skrull are biologically compatible with both Humans and Kree are able to produce fully viable offspring.
The Skrull empire is spread over nearly 1000 worlds in the andromeda and surrounding galaxies.
The empire is currently divided amongst amongst the surviving members of the royal family since the succession was interrupted.
The Skrulls worship Kly'bn and his bride Sl'gurt
The Skrulls evolved on the planet Skrullos in the Drax system in the Andromeda Galaxy. Almost a billion years ago the early Skrulls were visited by the alien giants known as Celestials. Like they had done on many other planets, the Celstials experimented on the Skrulls ancestors and divided the species into three branches. The "normal" branch which while powerless had the potential for benevolent mutations, the shapeshifting Deviant branch and the near immortal Eternal branch. Like on many other planets, the Deviant and Eternal branches went to war and in the case of the Skrulls, the Deviant branch won and wiped out all of the normals and the Eternals, with the excepion of Kly'bn who convinced the Skrulls to spare him in exchange for becoming their everlasting embodiment of what it meant to be a Skrull. The leader of the Deviants, Sl'gurt accepted his offer and volunteered to become his bride. Since Kly'bn was to represent the eternal nature and true form of the Skrulls, Kly'bn vowed never to stay in a single shape for an exteneded time. The two would become the Skrulls gods.
In time the Skrulls abandoned their warlike ways and became peaceful and scientifically minded. Their shapeshifting abilities allowed them to make great contacts with other alien races by simply changing their appearance to look like them. The early Skrull Empire that resulted from these contacts was one based on free trade and mutual co-operation.
Eventually the Skrulls would voyage to the Magellanic Clouds where they discovered the Kree homeworld of Hala. The Kree and Coati who were the two races that shared the planet were still in the dawn of their civilization. The Skrulls decided to manufacture a test in order to determine which race was worthy of receiving Skullian aid and support. A band of Coati and Kree were transported to the Moon of Earth in the Milkyway Galaxy. Here the Skrulls created an artificial environment called "The Blue Area of the Moon" and left the two races to accomplish what they could. The Skrulls deemed the work of the Coati to be superior which greatly angered the Kree band who killed their Skrullian judges and Coati competitors. They stole the Skrulls advanced technology and due to the immense travel distances, it would take the Skrulls decades to learn of the Kree's activities.
By the time they did, the Kree had grown advanced and audacious enough to attack the Skrullian home galaxy which launched the Kree-Skrull war which would last for millennia. The Skrulls developed the vicious streak required for intergalactic war and with the millennia their entire culture was remade in the warrior image. The Skrulls would come across the Earth which held strategic importance in their war against the Kree and decided to attempt to conquer it. Afraid that the Kree would learn of a full scale invasion, they decided to initially only send a few agents. These agents were foiled by the humans however who had also been manipulated by the Celestials and whose "normal" branch was beginning to manifest super-human powers at a greater scale.
The humans strongest representatives would arrive on the Skrullian throneworld and demand that the Skrullian Emperor leave their planet alone. The same demand would be made towards the Kree who had also gained an interest in Earth. The Skrulls would send many agents in an attempt to subjugate Earth but no full scale invasions.
Eventually the Skrull throneworld was consumed by Galactus, a cosmic force of nature who devours planets in order to maintain the cosmic balance. With the loss of their central government the Skrull Empire collapsed into several warring factions with each governor declaring himself "emperor". The Skrulls would only fare worse when they were one of first major interstellar empires to be targeted by the Annihilation Wave. The Annihilation Wave was a gigantic army that came from the Negative Zone, a Universe outside our own. The Annihilation Wave's superweapon, the Harvester of Sorrows would destroy 90% of Skrull controlled planets before it was destroyed by a Skrullian champion; Kl'rt. With their empire decimated, a large faction of Skrulls lead by the extremist Queen Veranke launched an all out invasion of Earth.
Veranke was a religious extremist and was convinced that the Skrullian holy texts promised the Earth as a new throneworld for the Skrulls. Using their shapeshifting powers, the Skrulls replaced several of the Earth's superhuman heroes and several key members of both major criminal, terrorist and police organisations. With the worlds greatest heroes incapacitated, the majority of its superhuman populance (the mutants) de-powered (prior to the Skrull invasion) and with mistrust spreading among the humans, the invasion seemed guaranteed. But failure would come when Reed Richards, a human genius who had opposed the Skrulls since he first learned of their existence used a device to pierce through the Skrull's shapeshifting. With their enemies clear before them, the Skrull's fleet crippled and with all the heroes and villains united, the Skrulls would fail in their invasion, thus decimating the once mighty Skrull Empire.
With their Empress dead, the remaining Skrull worlds fell into civil war once again. Eventually, six Warlords rose to prominence. By this time, the ancient race known as the Builders invaded several space empires, among them the divided Skrull territories. An alliance was created, and the Skrull warlord Kl'rt was chosen to represent their people and lead their armies. Kl'rt and the rest of the generals led the alliance to victory, and for his great actions, Kl'rt was crowned Emperor of a reborn Skrull Empire.