In 2283 humans discovered they were not alone in the universe. First contact was made when a scout-ship of the Aleos, searching for colonizeable planets, crash-landed near the 3rd Mars colony, Harris. There were two survivors.
When the search and rescue crew arrived they found the two survivors being cared for by the colonists.
The High Council of Aleos decided on diplomatic relations with the humans on the condition that the colonists of Harris are chosen as Earths ambassadors.

Taking advantage of the new technologies shared by the Aleos, CerTech became the first human company to design and manufacture civilian and military starships. But because the human race was considered primitive by most and was still new in the Galactic community, human built ships were considered inferior by other races and were mainly used in the Terran fleet.

In 2515 The Alliance was in it's 45th year of a conflict with the warrior race Rok, and they were losing. Each battle pushed the Alliance back one system at a time.
In that same year, the Rok attacked a human colony at the edge of the Alliance controlled territory. The Alliance could not help, as the bulk of their fleet was already engaged in battle. The Terran fleet, comprised mostly of the CerTech built Magnus, a Dreadnought class ship,  defended the colony for two months and eventually defeated the invading Rok, marking the first victory against them. Five ships and over 200 soldiers were lost in that battle.
The belief that humans and their technology were far inferior was changed over night, and the Human race was asked to joined the Alliance and the war against the Rok.
In 2520 after 50 years of war the Rok were defeated and pushed back to their homeworld.