Emerald Cove was a UEG colony world.
SPARTAN-II Training Edit
During their training, the SPARTAN-II's were sent on an underwater mission with Chief Petty Officer Franklin Mendez. Mendez sabotaged half of the Spartans' air tanks and in return, they stole his. They then, as Anton-044 humorously put it, "ditched him and camped out on an island for a week, with nothing to do but light bonfires, bake clam, and surf". It was a good memory they all enjoyed sharing.
Later History Edit
In 2542, the UNSC abandoned Emerald Cove due to the danger from the Covenant. There is no information on whether or not there was any combat in the abandonment and/or evacuation. The planet may have been glassed but was likely not even located by the Covenant due to no significant human presence.