Revolution
The rebellion of the enslaved dragonborn against the dragons still keeping them.
The dragonborn had been enslaved by dragons since their creation in the Strife of Yacimen. The dragons were neglectful at best, and cruel at the worst. The dragonborn, following the example of the warforged, rebelled. The dragonborn rebellion did not have an easy start; the dragons may have been weak from the fall of the inquisition, but they were still legendary creatures. However, the warforged took pity on the dragonborn and assisted their rebellion in return for help in theirs. The warforged and dragonborn together managed to free the dragonborn race, but the dragons would find new slaves in time. These former slave races then went on to found Parthurnax, the free city.