Fall of Arcadia

After the First Battle of Arcadia, the Covenant left the colony alone, their attention focussed elsewhere. The UNSC mostly abandoned it, leaving its population centers abandoned to nature. A small rural community started Abaskun, a fertile area on the continent of Mu, and though self-governed and mostly lawless, it provided the UNSC with much-needed foodstuffs until the colony was attacked when the Covenant returned in 2549, almost eighteen years since their last visit.