The Diaspora of Man was the migration of various groups of humans from their home planet of Earth to other inhabitable worlds of the Galaxy.

Historians placed its beginning on September 30, 2103 CE, when the colony ship Prometheus left the Sol System. In the new time reckoning adopted by most of humanity in the following centuries, 2103 became year 1 Post Diaspora. The first extrasolar colony of mankind was the planet Beowulf in the Sigma Draconis System. (UHH)

The early colonization efforts were overseen by the Outbound Operations Administration; the Earth Union government of the 3rd Century PD almost brought these efforts to a stop due to the influence of the Earth-Firsters and other anti-expansionist groups. However, after the Economic Winter of 252 PD and a subsequent change of power, a long era of prosperity and expansion began. (HHA6.1: BTB)

Over the centuries, thousands of planets were settled, some with more success than others, and numerous large and small star nations formed in a sphere of roughly 200 to 1000 light-years around the Sol System. The core worlds surrounding Earth were the most developed, and eventually founded the Solarian League. (UHH)

Genetic engineering of human beings became very common during the Diaspora; many colonists were artificially adjusted to life on their new homeworlds, causing physical distinctions unlike those common among pre-Diaspora humans. (HH9, CS1)

Humans also encountered a number of other sentient species. One of these encounters went extremely badly, when the human settlers on the planet Barstool wiped out the native Amphors. Other first contacts, like that with the Sphinxian treecats, were more successful. (SK1)