Construction of Nos Varda began when mass transit links were laid across the Cold Claw Gorge, a geological formation to the west of Nos Astra which until then had curtailed intensive development in that direction. With Nos Astra's urban sprawl having encompassed much of the easily-accessible land in other areas, and property prices becoming prohibitively high for developments requiring large land areas, the Cold Claw/Nos Varda project was implemented to create a new expansion zone. The resulting city - relatively distinct from Nos Astra, although administratively considered part of it - became home to much of Nos Astra's new-built manufacturing and commercial warehousing industries, as well as a number of residential areas catering both to Nos Varda's own workforce, and commuters working in Nos Astra, for whom the city offered much more spacious accomodations than would have been possible for the same price in Nos Astra proper.
When news reached Illium of the Reaper invasion, Nos Varda was identified as a suitable evacuation site for the population of Nos Astra - although overcrowding was a concern, the city's massive power plants, intended for heavy industry, were sufficient to provide for the needs of the sudden influx of refugees and the hydroponic and airponic agriculture complexes necessary to feed them, as well as defensive measures such as high-yield barrier generators. Upon the Reaper landings on Illium the bridges across Cold Claw Gorge were destroyed (delaying long enough to take a significant number of husk ground troops with them), creating a natural barrier between Nos Varda and Reaper-occupied Nos Astra. With ground access to the city now possible only via the southern coast or the lengthy, exposed northern approaches, Reaper forces found it much more difficult to approach the city without suffering problematic losses from hit-and-run air strikes. In combination with the city's barriers, defensive heavy weapons, and the bolstering of its huntress cadres with troops from the Eclipse Corporation, Nos Varda was able to weather the continued low-level probing attacks, and survive (though sometimes narrowly) the occasional more concentrated assaults, until the eventual Reaper retreat.
With Nos Astra uninhabitable due to massive structural damage, as well as concerns about the potential effects of any Reaper technology which may have been left behind, the former city was not immediately reclaimed. Instead, Nos Varda was expanded in a number of government-funded and corporate-partnership new-build programs, creating more suitable accomodations and workplaces for the millions who had sought shelter there during the war. One of the first acts of the reestablished planetary Board of Governors was to formally rename the city Nos Astra and confirm its status as capital, while the slow process of clearing and reclaiming the old capital site began.
'Nos Varda' is still used informally to refer to the original site of the city, which now consists of several districts in the centre and central-south of Nos Astra. While the expansion rapidly moved beyond Nos Varda's old borders, a segment of the defenses (with weapons disarmed) and barrier generators was preserved as a monument and tourist attraction.