Arcadia

Based in the Procyon system, Arcadia was a colonial planet which needed no aggressive terraforming measures when it was first considered for human habitation. In fact, covered in densely lush forests and jungles—many of which remained unexplored for decades—the world had an incredibly plentiful supply of all the ingredients needed to support human settlement.

Like many Outer Colonies, Arcadia would quickly find itself exploited for agricultural and recreational reasons—becoming both a farming world and a tourist destination. But the planet was not limited to these two industries: Arcadia was also the site of the Deep Space Research Array, leading some to point out the irony that the Arcadians knew more about the heavens than they did about the dense jungles of their own backyard.

Arcadia had six designated continents: Eire, Pacifica, Mu, Caledonia, Lemuria and Avalon—and within each of those a number of provincial regions exist, the most popular of which was the metropolitan capital of Pirth. This was quickly discovered by the Covenant upon their arrival in early 2531, and they focused a significant amount of their local resources on an effort to destroy it.

Though UNSC forces would eventually push the Covenant back, it would reveal what they were ultimately looking for. Buried deep within its jungles, Arcadia held a series of ancient structures which predated humanity’s presence—structures which would later be revealed as Forerunner. These relics led the Covenant to a shield world—a Forerunner installation created as a shelter against the firing of the Halo Array.

While the Covenant would leave Arcadia only days later, they would eventually return in 2549 to obliterate whatever remained. When they arrived, the Covenant found the surviving Arcadians in a bizarre, anachronistic state—flora had overgrown their cities and whatever remained of their civilization had slipped into a state of lawlessness.

Even in that dark hour, many Arcadians would do what they had always done: continue to plant and grow crops for the Inner Colonies, clinging to their trade and whatever vestiges of civilization still remained.

That is, until the planet was wiped out by the Covenant almost two decades later.