Revolt of Sapphire Isle

The Revolt of Sapphire Isle was a rebellion that saw the ambitious lord Tarth attempt to carve out power for himself using his wealth and connections. It took place in the same year as the War of Oakheart Succession, with the latter breaking out a short while after the Stormlands was engrossed by war.

Background
Lord Lyonel Tarth in his day was one of the wealthiest lords in the Realm. Ambitious, energetic, and above all, creatively eccentric, the Lord oversaw the expansion of his island's famous emerald mines to become one of the jewels of the eastern shores. His wealth only propelled even greater as the ravages of the Wine Wars saw his port become one of the few safe ones to trade at. Though wealthy beyond even his lieges in Storm's End and by all accounts a successful man whose legacy could have seen his island be a second Arbor, such was not enough for him. Lyonel sought promotion beyond his rank and so found the Small Council to be his greatest conquest. However, while intelligent, now the overconfident lord let his ambitions be laid bare, grievously insulting King Maelor as he demanded the council seat he thought was his by right. Not only was his request flatly refused but Lyonel found himself pushed out of court life entirely and effectively booted back to the emerald island. This would not do.

The Revolt Begins
Since his disgrace at court, the Lord went silent for the next year, only to reemerge at the shores of the Stormlands on the heels of a great mercenary army hired with his decades of fortune. Though at first seen as a minor threat, it soon became apparent that Lyonel had prepared more than a mere mercenary army and had agents spreading propaganda, that he had been defamed for attempting to grant the peasants greater rights, remove the harsh trade tariffs that had so irked the merchants, and share the wealth of Tarth with all. The first army sent in response to his invasion would not even reach Lyonel’s force; melting away in waves of desertion with its loyal knights cut down in fierce guerilla campaigns by locals across the Rainwood. Lyonel had gained the momentum and had already won a great victory without a single loss of his own.

With disloyalty rampant and ambitious lesser knights now defecting to the invaders, the Stormlanders desperately attempted to pull together a new force to defeat the growing threat only for the same cycle of desertion to destroy their efforts. Realizing that most of their own peasants were compromised, Lord Baratheon called upon loyal units from the Marches to assemble a force and grudgingly called upon King Maelor to restore order.

The monarch, who'd so recently put down a revolt against him in the same lands, ventured forth once more, the armies of the Crownlords in tow, though Lord Darklyn opted to stay behind in his demesne for the time being. The first engagement occurred at Truestone, where Maelor's forces were ambushed in the dead of night, by Tarth's brash and arrogant sellsword captains. The Battle of Truestone proved an utter disaster for the mercenaries, as the King mounted a brisk counter-attack, repelling the presumptuous foe. Breaking this army gave his own some time of respite, as the Velaryon continued to march through the Stormlands without interruption, intending to join with the other Stormlords.

Meanwhile, Lord Trant struggled against the joint strength of deserters from his army, and Lord Tarth's warriors-for-hire, suffering defeat in the Battle of Gallowsgrey, being forced south. Lord Wagstaff and his meagre batch of retainers barely squashed a peasant uprising of their own, in a pyrrhic victory, after which the nobleman is said to have wept for both his knights and the lives of his smallfolk, for which the event was dubbed the Woe of Brassfort.

While Lord Tarth used a part of his armies to extend control over the Kingswood, the other moved southwest, to attack castles like Nightsong and Blackhaven. Maelor, as it seemed, had ambuscades of his own. Near Harvest Hall, at the Cockleswent, the army of the Crownlands lay patiently in wait. The King was reputed to be a great scholar as well as a brilliant general (or perhaps due to it), never willing to part with his books, and thus he kept a mobile library with him at all times. In time, the Crown's subjects became accustomed to the fact that alongside normal cargo and supplies armies were generally expected to carry, Maelor would also be accompanied by a plethora of tomes. Such was his passion for book reading, that he almost missed out on participating in the very ambuscade he'd planned, engrossed by another literary work. The cries of his squire eventually roused his senses, and he plunged into the conflict headlong, labeled the Bleeding of the Cockleswent, or more famously, the Bookman's Battle. Afterwards, he linked up with minor Stormlords who'd been beaten back by the sellswords, but still retained a miniscule of their power. Lords Dondarrion and Carron also pledged their knights' blades at earliest convenience, which the King prudently refused: although the enemy he faced was rabble, lacking in discipline and courage, they were not unlike vermin in their spread. Each time they ran, but they always did so before full decimation. Thus, the threat of them reemerging was a reasonable one, and Maelor preferred to have these two lords crush any such groups left behind, instead, while he marched east.

Storm's End was once more plunged in a dangerous position, for the bulk of Tarth's hosts were gathered in this region, dominating the Kingswood and routing any opposition. Having heard of reports from the West, Lord Lyonel decided to assault Maelor in the depths of the forestry, where he was the strongest. Yet the King knew of roads and pathways marked on the rarest of maps, and weaved his soldiers through the vegetation in a safe, orderly manner. Only when they got behind the sellsword army was the truth discovered. Naturally, a struggle ensued: the Battle of the Kingswood, which did not actually end in anything decisive for either side, despite the ferocity of Lords Fell and Wagstaff (alongside several others the King had collected on his journey). Tactics, discipline and courage were still hampered by the limitations of the common man. Like Aegon the Godswrath before him, he'd marched his men on a relentless, swift campaign, and inspiring speeches did little to alleviate fatigue. The two parties broke off after the mercenaries realised they could not break through the enemy lines, and the Stormlords saw it too dangerous to pursue the foe in their current state. No serious casualties were inflicted on that day, and the engagement is regarded more a skirmish than a battle by most.

News worse than that were yet to come: in the midst of this crisis, another had erupted, the runner claimed to Maelor - the Westerlands and the Reach had come to blows, and already scored a number of battles while the King had been occupied in the Stormlands. The information, of course, was severely delayed, as the majority of the messengers sent Maelor's way had been cut down in the Kingswood. Cursing, he left a portion of his armies in the Stormlands, making for the Reach at the break of dawn with the others.

Though the Stormlords were relieved, they could not utilize their advantage in full. All of them had differing opinions on how to best combat Tarth's tactics, and Lord Baratheon seemed indifferent to this particular conundrum, leading the noblemen to (non-violent) conflict, now that they lacked a royal authority to rein in their pride. The sellswords continued to maintain an active influence in the Kingswood, and Baratheon's subjects were ineffective in rooting it out. This in particular prolonged the war more than anything else. The men of the Stormlands failed time and again to actually encounter the main strength of the traitor, only coming across individual cells prone to ambush.

It was only when the two armies met that - combined with the fact that Lord Lyonel’s own army was deserting for the harvest or lack of pay - the force could be finally cornered and eradicated, with the few survivors fleeing deep into the Rain Wood first as guerillas but later as petty bandits, after the Second Battle of the Kingswood. Lord Lyonel himself was found attempting to slip away to Essos and was beheaded, with the mainline of Tarths being imprisoned, the seat of Tarth itself being given to a loyal branch of Tarth knights.

Aftermath
Though the war was never an existential threat (especially as the rabble army was virtually unable to take any large castles), the length of the affair and economic devastation it caused crippled the Stormlands and left the Crownlander levies drained, all for little gain, as even the treasuries of House Tarth had been emptied to pay for the armies.