Reign of Aegon VIII Targaryen

NOTE: The timeline does not add up. It says that the Dayne king reigned from 308-312 but that Aegon VIII is from 312-320 on the timeline. Its probably a typo but Aegon wouldn't be considered the actual king until he won the rebellion (which he did), so he couldn't begin reigning in 312 but rather in 314, making his actual reign 314-319, as I adjusted it to fit in without completely changing all of the other kings
The Dragon's Vengeance
The Dragon's Vengeance was a major military conflict, occurring in the Crownlands between rebels House Targaryen, and the crown House Dayne. The rebellion started in 312AB, finishing in 314AB. The war led to House Dayne's defeat, ending their dynasty, and signifying the ascension of House Targaryen as crown. House Egen also replaced House Lannister as the hand house. 
After Lord Aegon's rise, King Vorian II Dayne realised the threat posed with Dragonstone on the doorstep of King's Landing. Recognising this, he extended an alliance request, congratulating him on their victory. This alliance was accepted by Lord Aegon. This signified a proposed era of cordial relations between the two houses. However, this would all change anon. Shortly after the Dragonstar Alliance was brokered in 312AB, Lord Aegon's fleet carrying three armies arrived at the docks of King's Landing unexpectedly. King Arthur was initially confused, quickly become furious when the scale of Targaryen's betrayal became clear. Lord Aegon Targaryen planned on becoming King of the Seven Kingdoms, fulfilling Lord Rhaegar's legacy.
House Targaren's forces besieged from the docks, scaling the ladders and entering the city with ease. House Dayne's army situated itself on an inner wall, choosing to hold two elevated bottlenecks. However, this defender advantage would not aid the King's Landing Royal Garrison. Aegon's army took immediate control of the battle, pressuring Dayne's entrenched position, forcing them to fall back and give up their advantage of a bottleneck. This led to Targaryen's army putting the Daynish on the back-foot, allowing them to overwhelming the retreating force. Despite some pushes in which Dayne had brief control over the battle, the Targaryen army convincingly subdued the crown, beating them 5-2. King Aegon Targaryen was the new Protector of the Realm.
The Massacre of the Lionstar
With the combined House Dayne and House Lannister army besieging King's Landing from land, House Targaryen appeared to face their toughest challenge yet. Both armies where equal in size, but House Lannister and Dayne were debatably seen as the favourites due to their experience. A brutal battle would soon unfold.
Rather than playing passively as Dayne did as defenders, King Aegon took the fight to the attackers. This gave House Targaryen full control of the battle, consequently meaning that the Lannister's and Dayne's were permanently on the back-foot. This once again meant that the Targaryen Garrison overwhelmed the besiegers, allowing them to kill more whilst losing less. This approach led to a convincing 5-0 win. The dragon retained his crown.
== Aftermath ==
With House Lannister and House Dayne's defeat, no armies were left in the vicinity to King's Landing. As a result, the Dragon's Vegeance was fulfilled, with King Aegon VIII Targaryen winning the war, replacing Dayne as crown, and deposing Lannister as hand. With this latest beating, House Dayne and House Lannister backed down, signifying an end to the conflict.
However, the realm was still in a state of discord, with many enemies of the crown. This continued to include House Dayne, House Lannister, and now more significantly... their newly-appointed hand, House Egen. House Egen debatable had the strongest army in the realm, and they proved hostile. Consequently, they were replaced as hand with their current enemies, House Pemford.
A new war was ensuing. The dragon and the bird were to clash in the Strike of the Birds soon after.
Eight years later in 322AB, House Dayne and House Lannister would unite much of the realm to rebel during the United Realm War.