The Baratheon Succesion Crisis (The Grand Campaign)

The Baratheon Succesion Crisis
"For weeks we held our positions at the Trident, for weeks we waited on action... but we did not expect it to be us charging. Lord Damon Lannister rallied the loyalists and we charged into Atranta, without any tactics we joined the battle, a battle that was turning into a massacre. In the end 200.000 men will never return home because of one man wanting a throne.. but what he got was death by the plague. Bloody arse deserves it. - Unknown Soldier's diary"

The Start
Due to the untimely death of King Rodrik "Ironheart" Baratheon and the abdication of Prince Orys Baratheon, the throne fell to Torrhen Baratheon, at that time a justborn child. The realm was disgruntled with the fact that House Stark held all the power of the throne and they soon started their preparations for war.

House Chester and House Tarth were the first to openly declare Torrhen unworthly to rule and declare war to put Maric Baratheon on the throne, they were soon followed by House Martell, House Lannister, House Roxton and House Yronwyne declaring war on the throne for Aegor's claim, however they abandoned Aegor shortly after and joined Maric.

However, Lord Edrick Stark, the Lord of the North and Hand of the King, managed to find himself some allies in this crisis, House Belmore (though later in), House Tully of the Riverlands, House Lannister of the Golden Tooth (Going in against their own kin), House Ironstark of Pyke, House Hoare of Harrenhal and several other houses.

The Battle of Atranta
The only major battle in this war was fought in the town of Atranta, a small riverlander town sworn to House Hoare.

With the rebels slowly marching into the Riverlands, Lord Damon Lannister did not want to wait any longer and rallied his men and marched onto Atranta, that was under siege at that moment. At first it was around 20.000 men fighting a small sieging force.. but soon enough the rebels and loyalist alike sent in their entire armies. The battle counted atleast over 300.000 men. Either fighting for Torrhen, or against him. The river near Atranta was running red with blood after the battle, around 200.000 men were killed and the war was decided after this.

Aftermath
With their armies defeated, several lords surrender themselves to the mercy of the crown, however House Martell, House Chester and House Tarth decided to join the Blackfyres, whom decided to invade the Throne.