Kyreme

"Welcome to Gerina, the capital of commerce within the Milky Way Galaxy."

- Automatic shipboard message once in orbit of Gerina

Gerina was the arificial capital planet of the Forerunner (Ky'Leik) species and the species' primary government. At its peak circa 102,000 BCE, the planet held a population of over two-and-a-half trillion citizens on its massive surface. With the help of Forerunner engineering marvels, the planet's surface area was five times that of Jupiter's yet had a gravity of 0.81 G's, which was what the Ky'Leik were naturally accustomed to. Gerina is an ecumenopolis, meaning that its entire surface is a single city. However, millions of acres of agricultural grounds lie on the roofs of massive complexes across the planet. In orbit around the planet, a massive cluster of shipyards visible from the surface exist. The largest of these are able to build massive eight-kilometer long battleships in just days, not to mention their efficiency once their entire workforce had become Sentinel-like machines during the war against the Flood.