Before the Universe began, six singularities existed. Some time after the universe exploded into existence, these were formed into the six Infinity Stones by the Cosmic Entities. The Infinity Stones are six immensely powerful objects tied to different aspects of the universe, created by the Cosmic Entities. Each of the stones possess unique capabilities that have been enhanced and altered by various alien civilizations for millennia and represents a different aspect of the universe (Space, Mind, Reality, Power, Soul, and Time). Only beings of immense power can directly wield the Stones, such as Celestials, or the Mad Titan Thanos. Lesser beings face dire consequences: Jane Foster became ill after being exposed to the Aether and Carina exploded when she touched the Power Stone; however, these effects can be reduced if a group is sharing the power among themselves. It is also possible to place an Infinity Stone inside a container to prevent a person from directly touching it, allowing the user to wield the Stone's power without suffering the normal repercussions. Examples include the Space Stone inside the Tesseract, the Mind Stone inside the Chitauri Scepter, the Power Stone inside the Cosmi-Rod, the Time Stone inside the Eye of Agamotto, and all the Infinity Stones inside the Infinity Gauntlet.

Space Stone

The Space Stone has the power to control space, providing the user instant access to any location in the universe. Its original container unit was the Tesseract, a cube-like object which has been used as a weapon by many forces, including S.H.I.E.L.D., HYDRA and even Loki himself, while working for Thanos.

It was guarded by the Asgardians, the jewel of Odin's treasure room of relics, but lost during the last age of worship by men on Earth. In 1942, Johann Schmidt (also known as Red Skull, German SS officer and leader of HYDRA during World War II) found the Tesseract inside a church, T√łnsberg, in Norway, guarded by the Church keeper, who died by Red Skull's hands, and used its power as a weapon with the help of the Swiss scientist Arnim Zola. However, Captain America stopped them and Red Skull was banished to the planet Vormir when he touched the stone. Captain America crashed into the artctic along with the Tesseract during his final mission, before being found again during the 21st century.

The Stone was retrieved by the Strategic Scientific Reserve (S.S.R.) and was tested by Howard Stark, but lacking the recources of that time, he decided to leave notes for his son Tony Stark, so he can succeed where he had failed.

The Tesseract remained in S.H.I.E.L.D.'s care which sanctioned Project P.E.G.A.S.U.S. and tried to harness its power into advanced weaponry.

In 2012, Loki stole the Tesseract and used it to open a portal so Thanos' army, the Chitauri, can invade the Earth. The attack was stopped by the Avengers and the stone was sealed in Odin's Vault on Asgard.

During Ragnar√łk, Loki took the Tesseract with him, so it wouldn't be destroyed by Surtur. However, when Thanos attacked the Asgardian's spaceship and slaughtered half of them, he took the Tesseract from Loki and broke it to gain the Space Stone.