Battle Group Leviathan
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It participated in the Battle of Sigma Octanus IV in July 2552. More than twenty ships of the battle group were lost in the battle, with many more suffering heavy damage. After the battle, half of the battle group jumped to Reach while the rest stayed behind to maintain a level of readiness in the case the Covenant returned. The first group arrived at Reach on August 1, with the rest following on August 12.
The battle group engaged the Covenant Fleet, with most of the ships destroyed except for UNSC Gettysburg, which lost its entire crew while it was docked intact at one of Reach's refit stations. After the Fall of Reach and the Battle of Installation 04, Gettysburg was salvaged and used in Operation: FIRST STRIKE.
Afterwards, any survivors from the fleet were recalled to Earth and consolidated under the UNSC Home Fleet to make a final stand against the impending Covenant invasion.
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