Millennia ago, the people of Tegalus served the Goa'uld, but as time passed and the people were left abandoned, their culture began to develop. Some still believed in the "great gods" and that the "Great Ring of Avidan" (the Stargate) was a source of the gods' power.
Tegalus is a world of warring superpowers with deep-seated political differences. The two major powers, the Rand Protectorate and the Caledonian Federation, had been locked in a state of cold war for decades. Despite a level of technological development similar to the 1940s and no capability of reaching orbit, each nation controlled enough weapons to wipe the other off the face of the planet. (SG1: "Icon")
Arrival of the Tau'riEdit
When Stargate Command activated the Stargate on a first contact mission, it happened in the public museum where the "Great Ring" was kept. Before this, the people who retained faith in the great gods were dismissed as fundamentalists, but the arrival of the Tau'ri fueled the religious underground, proving their faith was correct. The Caledonian Federation enacted a state of martial law when the news broke to prevent religious fundamentalism from taking root. The Rand Protectorate refused to follow that route, and the fundamentalist unrest became an insurrection.
Eventually Soren, the leader of the zealots, staged a successful coup, taking control of the Rand Protectorate's government, and cities, including the "Great Ring". The Caledonian Federation, in fear of the instability of Rand, launched an attack to prevent rogue weapons firing on them. Soren countered with the weapons he controlled and a global war broke out. When the dust settled, Soren was in control of Rand, and the main population centers of both countries were destroyed. Soren renamed Rand "Avidan", a Goa'uld word meaning "the gods are just".
Dr. Daniel Jackson, injured and stranded on the planet, tried several times to make contact with the SGC using a more primitive Rand radio on the farm of Leda Kane. Stargate Command attempted to negotiate with Soren, but he refused unless they gave him weapons with which to take over Caledonia. During this time, Daniel finally made contact with the SGC. Daniel, Jared Kane, and a few other loyalists, stormed the bunker in a coordinated attack with SG teams led by Lt. Colonel Samantha Carter coming through the wormhole. In this attack, Kane killed Soren. (SG1: "Icon")
- Main article: Battle of Tegalus
Less than one year later, while still rebuilding from the war, Tegalus was visited by a Prior of the Ori. Coming through the Stargate, the Prior first encountered the population of the Rand Protectorate. At first resistant to their demands to serve the Ori, they were struck down by the Prior Plague. Thousands succumbed to the disease before President Nadal submitted to the Prior. The Prior wished to spread the word of the Ori to the Caledonian Federation, but old rivalries between the two nations prevented that.
As a reward for embracing the Ori, the Prior offered Rand power. Under the Prior's direction, Rand developed a satellite weapon powered somehow by the Ori. They also wanted Rand to break off all ties with Earth. Since the SGC was not providing them with weapons to fight Caledonia, Rand was more than happy to oblige. Jared Kane, fearful of this new weapon and tired of all the death, secretly came to the SGC to warn them of the Prior and this new weapon.
Kane and Dr. Daniel Jackson returned to Tegalus to try and talk President Nadal into dismantling the weapon. They were arrested as spies. Meanwhile, the SGC launched Prometheus to destroy the Ori weapon if Jackson's diplomacy failed.
When the Prometheus arrived out of hyperspace above Tegalus, it attempted to destroy the satellite, only for the efforts to fail as the satellite was protected with the shields.
In response, the satellite fired two shots, dealing overwhelmingly catastrophic damage to the BC-303 while also killing some of the personnel on board as well.
Despite Lieutenant Colonel Samantha Carter's efforts to repair the ship, it ultimately failed as time ran out. Not wanting his crew and SG-1 to die, Colonel Lionel Pendergast was able to beam most of the surviving crew down to Caledonia before a third and final shot destroyed the Prometheus, killing Pendergast as well as any crewmembers who couldn't beam out in time.
Minister Chaska of Caledonia provided the survivors of Prometheus refuge. Together they figured out a way to use an F-302 fighter-interceptor to disable, and hopefully destroy the Ori weapon. Jackson was able to broker a temporary truce while the weapon was disabled. In exchange for Caledonia not destroying the weapon, Rand would allow those Caledonians who did not wish to follow the Ori to leave. This truce was almost broken by the fanatical betrayal of Nadal. However, he was stopped, and also shot dead, by his second in command, Commander Goran Pernaux, who insisted the truce be maintained.
During the cease fire, the crew of Prometheus, including SG-1, returned home. Soon afterwards, it was revealed that the peace talks had broken down. Caledonia did not wish to leave their home and attacked Rand, which responded in kind. Both countries destroyed each other, and the Stargate was presumed buried in the rubble. After losing contact with the planet, the Daedalus was dispatched by the Tau'ri on its way back from Atlantis and discovered the aftermath. (SG1: "Ethon")