Domus Diaspora

Domus Diaspora is the historical term applied to the period of rapid interstellar colonization that began in the early twenty-fourth century. This period of humanity's history saw the mass exodus of huge numbers of colonists, enabled by the discovery of faster-than-light travel, headed for alien worlds beyond the bounds of the Sol system. This explosive growth would result in over 800 habitable worlds falling into the UNSC's sphere of control and, within two-hundred years, billions of people would be living and dying outside of the Sol system. However, this period also laid the seeds of future conflict, creating tensions that would eventually erupt into the Insurrection.

History
In the late 21st century and throughout the 22nd century, humans expanded from the overpopulated Earth to colonize other worlds in the Sol system, including Luna, Mars, and the Galilean moons of Jupiter. However, as new philosophies spread among these new colonies, new factions with militant ideologies rose to oppose the United Nations and its Unified Earth Government. These conflicts eventually led to the Interplanetary War, fought across Earth and humanity's new colonies. The war was brought to an end with the United Nations' newly established United Nations Space Command, formed with the consolidation of power with Earth's technocrats. In the aftermath of the Interplanetary War, the Unified Earth Government rose to power as the dominant governing body of humanity's colonies, with the UNSC serving as its subordinate military branch.

The aftermath of the Interplanetary War left the Unified Earth Government with a different threat, overpopulation and a massive military with no enemy to fight. The post-war period saw massive growths in population on Earth and on her colonies, as well as increasing famine among the populace bred from the Rainforest Wars. These situations threatened to destabilize the economy. However, in April 2291, a team of researchers, physicists, and mathematicians led by Doctors Wallace Fujikawa and Tobias Fleming Shaw saw the invention of the Shaw-Fujikawa Translight Engine, a device that allowed ships to travel slipstream space to traverse interstellar distances. In 2310, the Unified Earth Government unveiled their first line of colony ships, designed to bring rigorously tested, highly qualified colonists and military personnel to settle nearby worlds. In theory, only the best-qualified citizens and soldiers were allowed to colonize humanity's new colonies, leading to the formation of the Inner Colonies. As colony ships were built in ever-increasing numbers, the trickle of colonists became a mass exodus from the Sol system, leading to the Domus Diaspora.

It was at this time that the Colonial Administration Authority was established by the Unified Earth Government as an agency tasked with the governing of human colonies and the direction of further colonization efforts. The Colonial Military Administration was formed alongside the CAA, to serve as the military body responsible for protecting the UEG's extra-solar colonies, while the United Nations Space Command largely kept their operations confined to the Sol system. The first colonies formed in the Domus Diaspora were established on verdant worlds and above resource-rich moons. As early terraforming efforts were a lengthy process, already habitable worlds—however rare—were preferred by the UEG's expansion effort. Habitable worlds that could be quickly reached through slipspace soon housed sprawling cities and orbital factories connected through trade and the influence of massive interstellar corporations. Despite early successes, for the first decades of the Domus Diaspora, colonization efforts faced significant challenges in marshalling political and economic support. The Epsilon Eridani system, home to several worlds within the habitable zone of the system's host star, became a prime candidate for colonization efforts. On January 1, 2362, Odyssey and a fleet of other colony ships were launched to Epsilon Eridani to colonize Reach, and Tribute and Circumstance in the following years.

Following colonizing successes and improvements in slipspace navigation spurred further exploration increasingly distant from Sol. For a time, much of the Unified Earth Government's resources were directed towards further colonial expansion. By 2390, the Inner Colonies were formally established, consisting of 210 worlds in various stages of terraforming. The population burden across human space had largely stabilized in the Domus Diaspora. In subsequent years, the Inner Colonies exponentially grew and prospered, drawing in investment and building infrastructure extensive enough to become self-sufficient and send their surpluses back to Earth. Meanwhile smaller colonies and outposts of the greater human civilization spread ever outward along slipspace routes from this developed and tightly controlled zone to become the Outer Colonies.

Trivia
"Domus, -ūs" is a Latin word meaning "house" or "household"; while "Diaspora", from Greek, refers to "the movement, migration, or scattering of a people away from an established or ancestral homeland". This is therefore an appropriate name for humanity's period of interstellar travel, as masses of people left humanity's homeland in the Sol system, just as many Jews were forced out of Palestine or Irish out of Ireland in other well-known diaspora.

List of appearances

 * Halo: Evolutions - Essential Tales of the Halo Universe
 * From the Office of Dr. William Arthur Iqbal
 * Halo: Fleet Battles
 * Halo: Ground Command