The alien species known as the Kree developed and built the Sentries to watch over their military advanced bases and supply depots throughout all the Kree Empire and beyond.

Some 80.000 years ago, in Kree year 1220, Kree scientist Bronnek developed the prototype Sentry and the Supreme Council of the Kree Empire began to mass-build Sentries for military purposes. Hundreds of thousands of Sentries were built, although only a few thousands are currently active.

Sentry 213 was the first Sentry sent to the Earth's system, and it was placed in a little surveillance/supply deport in the surface of Uranus. It was discovered by an exiled group of Eternals, who proceeded to destroy the Sentry and invade the depot.

The second Sentry sent to your system was Sentry 459, which was to escort a team of Kree scientists wanting to research the most advanced life form of the system some 25,000 years ago. The Kree noticed that Earthlings could evolve to become advanced beings similar to the Eternals, so the Kree performed their own experiments, creating a genetically-advanced tribe that would become the Inhumans. The scientists left, but Sentry 459 was programmed to keep Inhumans under surveillance, monitoring their progress to civilization. The Kree wanted to use one day Inhumans as an army.

Millenia after that, Inhuman genetist Randac discovered the mutogenic Terrigen Mist, that could genetically alter his kin. Sentry 459 activated by the first time and contacted its leaders. After that, it returned to its hiding place and remained there for some millenia.

During the mid-20th century, archaeologist Daniel Damian discovered the advanced subterrenean base of Sentry 459 in a small island in South Pacific. The Sentry re-activated due to the alarm system and contacted its masters again. One of the surveillance deviced attracted the attention of Fantastic Four, who were near the place on vacation, and the Sentry fought them. However, the Fantastic Four defeated the robot, freed Damian and his aide and escaped^[1]. The Sentry was later placed under custody of the United States and taken to Cape Canaveral.

Due to this defeat, the Kree sent their main agent: Ronan the Accuser went to Earth.

A Kree agent, Colonel Yon-Rogg, managed to get access to the Sentry and reactivate it. Yon-Rogg was the commander of a Kree reconnaissance mission on Earth, and also an enemy of his own agent, Captain Mar-Vell. Yon-Rogg wanted the Sentry to fight and destroy Mar-Vell, but Mar-Vell defeated the Sentry.

Ronan re-activated the Sentry after that, and used it in a scheme to invert the evolution in Earth. The scheme failed miserably and Ronan abandoned the Sentry on the North Pole of Earth.

Kree agents Mac-Ronn and Tara found the Sentry and erased its previous programming and memories. They loaded the Sentry on their ship but, before the could escape with it, S.H.I.E.L.D. intercepted their ship and they were forced to dump the Sentry. It fell near Mexico City and went rampage, until stopped by Mar-Vell.

The Sentry 459 was eventually destroyed by Ronan.

Powers and AbilitiesEdit

Powers

Auto-repair: A Sentry can repair itself unless it is destroyed.
Communications: A Sentry can transmit and receive data from the Kree at lightspeed. As the Kree live in another galaxy, most of the communications are not urgent.
Energy Beam: Sentry 459 could shoot a powerful energy beam from his eyes.
Robot: Due to its nature, the sentry is protected by the sheer strenght of its hull. It cannot be affected by emotional or mental attacks, nor by illusions. However, he is susceptible to attacks affecting machinery.
Strength level

80 ton range.