Greyhawk > From the Ashes
Or maybe a better title would be "What The Hell Are We Going To Do Now?"

When Ivid V ascended the Malachite Throne (also known as the "Fiend-seeing Throne") around 550 CY, the Great Kingdom had already crumbled and lost much of its power and influence. Unbeknownst to Ivid V and the rulers of other regions, two other powerful forces were putting plans in motion which would shape the future of Greyhawk.

From the Howling Hills in the north came tales that would turn ones blood to water as an overlooked ruler called Iuz began to expand his domain.
Refugees fleeing the lands told astonished Furyondians of Iuz's unbelievable evils: massacres; a road of skulls built from the Howling Hills to his new capital of Dorakaa; and watchtowers along the road with beacons fed on the fuel of human fat and flesh.

From the mysterious lands in the south came the discovery of a monastic sect called the Scarlet Brotherhood. In the isolated city of Kro Terlep, the Father of Obedience had been plotting for decades, installing red-robed agents in places of power, whispering in the ears of rulers, gaining trust and guidance. And when the time was right to strike, he did so with ruthless precision.
The Greyhawk Wars > 582-584 CY
"From the Hold of Stonefist" came the first cries of war as the organized barbarians, inflamed by the appearance of the "Vatun, the Great God of the North," swept into the Duchy of Tenh, conquering it swiftly. Iuz easily toppled the Heirarchs of the evil Horned Society with the help of powerful fiends, making the streets of Molag run red with blood. The Old One then struck into the Bandit Kingdoms and Shield Lands, taking Admundfort and Critwall.
Furyondy was able to hold its eastern border at the great Battle of Critwall Bridge in CY583. However, a huge humanoid force advanced on Chendl, the capital, and took Crockport. After suffering many losses, the capital was saved.
The Great Kingdom entered the war in late 583 CY, striking north into the Phostwood, south and southwest into the Iron League, and west through Almor and on toward Nyrond. The Aerdi forces fought into the winter, where reports of Scarlet Brotherhood activity in the Lordship of the Isles and among the Sea Barons became apparent as leaders were replaced with supporters of the Brotherhood.

In the Spring of CY584, Turrosh Mak and his humanoid armies burst out of the Pomarj, conquering the eastern half of the Principality of Ulek and the southern lands of the Wild Coast.
To the north, the horsemen of Ket raided and took Bissel, while
"from the Crystalmist Mountains, great forces of giants and humanoids swept down into the Grand Duchy of Geoff, Sterich, and into the Yeomanry. In the latter, they were repulsed by peasant levies as worthy in battle as many seasoned veterans. Geoff and Sterich fell, the Keolandish armies too distant to oppose the invaders."
Many rumors abound regarding "the giant troubles" as they have come to be called. Some blame Iuz in league with evil Zuggtmoy (recently freed from her prison in the Temple of Elemental Evil), while others say Lolth and her drow schemed with the giants. Others naturally blame the Scarlet Brotherhood...but no one knows exactly why the giants invaded...just that they did.
There were some victories in CY583 as Iuz was prevented from fully conquering Furyondy and it's capital, and Veluna held off the Kettite incursions as best they could.

CY584 brought new assaults from Aerdy as Overking Ivid V took the field with his armies. He was completely routed at the battle of Innspa, and his response was to execute his battle leaders, his nobles, even servants, sages, and serfs. And then...using dark necromancy, Ivid raised them up as an animus,
"an undead being possessing all the skills and talents of the former living person."
The nobles of the Great Kingdom schemed and plotted and had Ivid assassinated...but then priests of Hextor...revivified Ivid who rose as an animus monarch. Executions were no longer enough for Ivid. Now he instigated wholesale massacres and genocide.
Bolstered by humanoids from the Bone March, the North Province seceded from the Great Kingdom, and then the animus nobles withdrew all support and the remnants of their armies from the Overking.
"The Great Kingdom was no more...so passes away the glory of the world."
As the war drew to an end, disturbing news Agents of the Scarlet Brotherhood had undermined the unity of the Iron League, and when the Great Kingdom fell apart, the Scarlet Brotherhood demanded the surrender of the Iron League states. When they refused, assassins slew nobles and rulers by the score. The Sea Princes, Onnwal, Idee > all fell to assassins and armies from Hepmonaland as the Brotherhood secured an iron grip on the Azure Sea.
However, not all of the Iron League was lost. Cobb Darg of Irongate either executed or exiled all of the Scarlet Brotherhood agents in his city. Sunndi still stood, its formidable natural defenses of hill, woodland, and swamp defying all attempts made against it.

So, what would become known as the Greyhawk Wars saw its end in the month of Harvester, 584 CY. In the Free City of Greyhawk, countless ambassadors assembled to inscribe their names on the treaty at the Day of the Great Signing. And even on this day, evil was afoot, as a fierce magical battle erupted in the Grand Hall and
"spread havoc through the Old City. Afterwards, two members of the famed Circle of Eight, the great mages of Greyhawk lay dead; Otiluke and Tenser were no more."
The blame fell to another Circle member, Rary of Ket, who was last seen fleeing with Lord Robilar into the Bright Desert > had Rary turned traitor and slain his old friends? Well, that tale is still in the telling.
Despite all of this, the treaty was signed and the Greyhawk Wars drew to a close.
585 CY, the Current Year > What You Know
"Evil is dominant in the north and south of the Flanaess. To the north, the lands of Iuz now stretch from the eastern Vesve Forest as far east as the Hold of Stonefist, and the Shield Lands and Bandit Kingdoms have almost wholly fallen to his reign.
To the south, the Scarlet Brotherhood controls the Sea Princes, the Lorship of the Isles, Onnwall, Idee, Hepmonaland, and unknown stretches of the Amedio Jungle.
The Great Kingdom is sundered, but while Ivid V rules a nightmare of a realm, the nobles who have succeeded him in so many realms are little better...there are horrors here which would whiten the hair of a hero barely entered into his manhood.
The Bone March is strong, and still threatens Ratik; the Pomarj is greatly expanded and threatens Ulek and Greyhawk; the vermin of the Lost Lands (as Geoff and Sterich are now known) threaten many states to the west.
Ket has subjugated Bissel as a vassal state; many Bisselites have fled to Veluna or the Gran March. In the Bright Desert, Rary the Traitor and Robilar are said to be subduing the savages and raising a force which might yet beset the Free City of Greyhawk. The Queen of Celene still refuses to give the help her western neighbors in particular need so desperately."
"Is all lost? Not yet. Nyrond still stands a pillar of Good; it is exhausted, spent of men and funds, but there comes no threat from once-great Aerdy, and Urnst is still strong in its defense to the west. Furyondy is beleaguered, still politically divided at times, but brave Veluna is still a land of glory and righteousness and supports its western neighbor also. Keoland and Ulek stand strong; the Yeomanry is an inspiration to good and brave hearts everywhere. And the barbarians are a law unto themselves, still raiding Aerdi, still supporting the brave folk of Ratik, still deeply hostile to the poisoned words from Stonefist.
The Theocracy of the Pale is intolerant, harsh, a land of hard hearts and harder words, but is not lost to evil. Sunndi still repulses all invaders, and the brave Free City of Irongate stands as a shining beacon of freedom among a swath of fell, evil lands. No, all is not lost yet.
The Free City of Greyhawk still stands also...Verbobonc and Dyvers and the honorable Highfolk, are still places where evil does not reign, and where muscle and sinew are bent to the cause of good.
No; all is not yet lost."