All differentiating qualities of the timeline are causally linked to the premature death of the Void Snake in 88 AC. The Aurobinian dwarves were most heavily impacted, but repercussions were also felt in light of the Void Snake’s ultimate designation as the only sephiroth of Charles Phoenix.
A note on timelines: A timeline is not a thing in itself, but rather a distinct course of events as a result of a specific revision of history. Due to the chaos of the oceans, causation between events rarely transmits among continents. This is significant because it means [a] any number of historical revisions could have occurred on other continents without impacting Aurobin-dô, and [b] that Timeline 3 does not affect civilizations that had not interacted with Aurobin-dô by 952 AC.
Other Aurobinian Timelines
All historical revisions in Aurobin-dô were caused by the Void Snake. Events before 88 AC are shared in common among all three timelines.
The first timeline ended in 951 when Charles Phoenix succeeded in his scheme to make the Void Snake his sephiroth. Phoenix had used his command over the Vloura to usurp Avandra’s divinity. He then came to learn about the Void Snake and, along with the Raven Queen, devised a plan to hitch his power to that of the Snake.
The second timeline originated with the end of the first in 951, and began in 88 AC (where/when the Void Snake began). In it, Charles Phoenix (who naturally would not be born for more than eight hundred years) starts as a full-fledged deity. The second timeline strongly resembles is predecessor because Phoenix was intensely worried about causing a paradox. The timeline was caused by a magic ritual during Manthyos Aux V‘s coronation and Phoenix could not risk that event not happening, so the deity did his best to reproduce the history that he knew despite unavoidable differences, such as his own inability to take on Avandra’s mantle. The timeline persisted until it was finally replaced in 952.
After the Void Snake was slain, a shard of the Void Snake’s essence, which had infected Charles Phoenix, took control of the deity and created a demi-timeline (akin to a demiplane) for its final fight against his fated foes. The timeline ceased to exist once Phoenix—and the Snake—were defeated.