Battle of Erebus was a skirmish between Stargate Command forces and Ba'al's jaffa on planet Erebus in 2003.
Prelude
At the same time when Daniel Jackson was ascended he witnessed Bra'tac and Rya'c capture by jaffa. He was unable to interfere and after he descended back his memory about this event was erased. Few time later he started to recall it. With help of Rak'nor he realized on which planet Bra'tac and Rya'c was imprisoned and Stargate Command launched rescue operation.
Battle
When Teal'c and Rak'nor failed to infiltrate labor camp unnoticed, Jack O'Neill launced "Plan B" - Samantha Carter and Daniel Jackson was sent to place bombs on Anti-gravity platform to destroy it along with half-finished ship and cause confusion within enemy force.
Their plan succeeded and, caught by surprise in a valley jaffa guardians became easy target for Tau'ri mortars and snipers. At the same time prisoners attacked their guard as well. Soon enough jaffa forces were destroyed. Rescued prisoners was evacuated to Alpha Site and then joined Jaffa Rebellion. (SG1: "Orpheus")