The Wars of Ascendency
The Wars of Ascendency refer to the three attempts that are known for draconic entities to attempt to break the Divine Barrier that separated the Material Plane from the Divine Planes.
The affairs of dragons are complicated, my love. We do not exist in your mundanity. We aspire to improve the status quo, or we posture. Its how we keep score, at the end of our days.—Criskira Klalkikarduud, Chosen Avatar of Sapphiros., The history of Tiamat, Volume Three: The words of Gwendolane
The three known epochs of the world of Kuselada are separated into The Priorae, The Intercessory & The Exinde. These epochs roughly correlate with the ends of the Three Wars of Ascendency of the Abbatchtkan Pantheon - the Dragons of lore.
The First War
The First War of Ascendency was initiated by the fate of Cerethys, the world mother. Her demise after siring The Nine (by her companion known as Titan) set forth a power vacuum that the adolescent children of the world mother struggled to fill. The War centered on the Brothers Diato and Xavarath, with the pair disagreeing on the importance of the material plane. After his eventual defeat by his siblings, Diato exiled himself into the Material plane as The Planar Lock was fabricated and used to seal the Divine plane. Diato's movements and life after the Priorae is poorly documented, and merits further investigation. It is in this dark age that the world turned into the Intercessory times.
The Second War
The Second War of Ascendency was initiated by Cwelgar; Turning the dragons against one another and using Diato's experimental beings to sow chaos allowed Cwelgar to disrupt the alliance of the Metallic dragons and gather allies amonst the chromatic. It seemed possible that Cwelgar would complete his ultimate goal - dethroning his siblings and taking on the mantle as Tiamat, the all consuming dragon. The events of the fall of Tinch in Abbatchtka and the time travelled adventurers known as the Joeshoes are well documented and explain the eventual failure of Cwelgar in his attempt to overthrown Bahamut, despite the almost complete demise of Tamarand.
The Third War
The Third War of Ascendency also involved the Joeshoes and is potentially the most complicated of the three. Despite Cwelgar's failure to dethrone Bahamut, significant damage was done to the pantheon, and the seed of rebellion were instilled. The fall of Tamarand allowed the Chromatic brethren to believe that they could be equals to Bahamut, and several attempts to escape the bonds of the Hasps were made. Ser Traintel, a pawn of the dragons themselves, started to investigate the lore of the world and attempt to undermine the safeguards of the hasps, often using adventuring groups (such as the Braves of Bahamut and Morrison's group) to gather artefacts and perform arcane rites to allow the chromatic dragons to escape their divine captivity. Erethian betrayed Cwelgar's trust at the end, usurping him and attempting to ascend themselves.
The Third war culminated in the Victory of Bahamut over the combined might of the chromatic siblings, though the damage to the planar lock was vividly clear to see by the god touched heroes who fought alongside her. At the end of the battle, with the Fall of Erethian heralding the ever-after, the Exinde.