Battle of Kallana

The Battle of Kallana occurred in 2005 during the Ori crusade.

Prelude
A Prior of the Ori came to the planet Kallana to convert its inhabitants to Origin. But the jaffa of the planet refused to follow the teachings of the book of origin and they were struck down by the prior, soon after a mysterious blue force shield appeared around the prior and the stargate.

The Battle
General Landry ordered Mitchell and his team to use any means necessary to stop the Ori. To that end, he sent along the military's latest superweapon, the Mark IX "Gatebuster" naquadria-enhanced nuclear warhead. He also sent the Mark IX's designer: Lt. Colonel Samantha Carter.

SG-1 traveled aboard the Prometheus to Kallana, where the force field has grown so large that it's visible from orbit. Mitchell, Daniel, Teal'c, and Vala managed to transport down to the planet's surface with the Mark IX. They tried to negotiate with the Prior, threatening to use the Mark IX in 30 “earth minutes”, but even the threat of imminent nuclear vaporization didn't budge him.

Suddenly, a bombardment of energy weapons rained down from above. Gerak, the leader of the free Jaffa, had learned of the Ori incursion and demanded to take matters into his own hands. At the same time, the force field expanded again. Out of options, Mitchell armed the bomb and transported his team back to Prometheus.

Humans and Jaffa alike braced for impact as the Mark IX detonated below. As the shockwave dissipated, they were stunned to discover that the force field had only gotten bigger. Gerak resolves to continue his bombardment of the surface, threatening to target the Prometheus once he has dispatched the Ori if the Tau'ri did not join him in his attack.

Mitchell gave the order to attack. Before long, Carter noted that their attacks were only making the forcefield bigger: The force field was using their attacks to power and increase itself, and as Nerus, who revealed he had been working with the Ori all along, informed General Landry, the Ori would have been unable to get this far without Earth's Mark IX. The Tau'ri plan had backfired.

Once the force field had engulfed the entire planet, a number of small, rectangular projectiles ejected from the Stargate, destroying two of Gerak's ships. Meanwhile, the force field began to collapse the entire planet into a micro-singularity. Gerak retreats as the projectiles come together, forming a colossal ring in planetary orbit. SG-1 gaped in awe as the first Supergate formed before their eyes. The Supergate, between 300 and 400 meters in diameter, powered by a black hole, was large enough to allow an Ori armada to enter the Milky Way galaxy.

Carter noticed that the pieces of the Supergate were becoming interconnected by a common energy signature. Vala, who realized that Gerak has left behind a cloaked cargo ship to watch them, used the transporter rings to board the ship. She moved the ship into the path of the last piece of the Supergate, disrupting its energy signature. When the planet finally collapsed and the micro-singularity formed, the shockwave destroyed the cargo ship and dispersed the now-inert pieces of the Supergate. The Ori beachhead was thus destroyed, and Nerus was sent to a prison underground in Area 51 until he can come up with a plan to fight the Ori.

Aftermath
After the first attempt at building a Supergate in the Milky Way galaxy failed, the Ori later succeeded in building one over P3Y-229, ultimately leading to the battle of P3Y-229.