The Photon Bomb's origins are uncertain, the first prototype was build by the now extinct species known as the Sytans which lived over 80 million years ago and were wiped out by an intergalactic flare. The first detonation was most likely the Drexler Event in which it inadvertently caused the extiction of 3,000 species, it is speculated that the Sytans saw the destructive power of this device and locked it, and all information about it inside the Grave of Giants on Blerreon VI. The Grave of Giants was further sealed when the intergalactic flare hit the planet and caused it to sink 4,000 meters under the surface.
The tomb was first discovered by Terrian treasure hunters when they stumbled upon it while drilling for pockets of crystalized Helium-3. They took the bomb and sold it to a Catalian drug lord, he stored it in his armory until it was raided by Terrian Special Forces and taken into their custody. Upon translation of the ruins engraved on the surface which read "He who would take this and use it for their own profit be cursed. Shall they never hold it's power over worlds." it was sent to Terra for further analysis which concluded that it was the single most destructive force ever created by an intelligent species.
It was reverse engineered and the first Terrian test was carried out in the interstellar space between the Gregeon and Latiri systems. The test was a success and the concussive shockwave caused a 12.8 planetquake on Latiri IV 17 years later. The first planetary test was conduced on a small forest planet known as Ankou 5, the resulting destruction was documented as the Ankou Beta 3 Event. The bomb was duplicated and 18 were produced, the Photon Bomb first saw combat in the Battle of Tysha 8913. The bomb was responsible for the deaths of 6.2 million Gorgenians and 3,590 Terrians. This and the use of 6 other bombs in separate battles is believed to be the main reason the Gorgenians signed the peace treaty.
The Photon Bomb was used in 18 conflicts in the following 300 years and was detonated hundreds of times, the secret of the bomb's design was kept for 80 years without it falling into enemy hands. The Gorgenians eventually decoded top secret messages from Terra and build the bomb. Tensions between the Terrians and Gorgenians were high and both sides threatened to torch each others colonies. The worst of the Cold War was ended when the small species known as the Catali bought the designs for the bomb from the Gorgenians.
There are now 6 species that have Photon Bombs and only 4 of them have ever used them in combat, it is estimated that there is between 500,000 to 2 million bombs in exitance today.