Burning of Quel'Thalas

The burning of Quel'Thalas was the attack on Quel'Thalas made by the Horde during the Second War in order to secure the help of their Amani allies. Initially, the Horde was capable of pushing the high elves all the way back to Silvermoon City, where a barrier was erected to halt their advance. The Horde eventually retreated from Quel'Thalas, finding the invasion futile for their purposes, and headed towards Lordaeron's Capital City, giving the elves the opportunity to push back and reclaim their lands.

Background
When the Battle of Hillsbrad Foothills broke out and the Second War was ignited, the grand commander of the Alliance armies Anduin Lothar sent a request to King Anasterian Sunstrider of the high elves, requesting that the elves repay the debt they owed the Arathi bloodline back in the Troll Wars. Being the last descendant of Arathor, only Lothar could make such a request. Believing that the orcs were not a threat to Quel'Thalas, Anasterian only sent a token regiment of elven soldiers. Ranger-Captain Alleria Windrunner would later follow up with a squad of Farstriders, believing that the orcs are a much greater threat than the high elves predict them to be.

In truth, Orgrim Doomhammer had no intention of invading Quel'Thalas. His goal was the Capital City of Lordaeron, as he believed that with its fall, the Alliance would fall apart. Before the war broke out, Doomhammer had encountered the Amani trolls that lived nearby, and they bonded over their shared hatred of the Alliance. Doomhammer offered them a place in the Horde, but the Amani trolls would not join until their chieftain Zul'jin was freed from Durnholde Keep. Upon his liberation, the trolls would be more than happy to bolster the Horde's ranks and provide them with their expertise of this unfamiliar land.

Towards the end of the Battle for Hillsbrad Foothills, Doomhammer personally led a raiding party to Durnholde and liberated Zul'jin, repeating his offer to the chieftain. Zul'jin initially balked at the proposal, claiming that the Amani trolls would not be slaves for anyone. Doomhammer explained that that was never his intention and that he wanted the trolls and the orcs to be equals in the Horde. Zul'jin was intrigued, but would only accept such an offer if the Horde helped him destroy the kingdom of his nemeses, the high elves of Quel'Thalas.

The invasion of Quel'Thalas
Doomhammer saw no harm in such a proposal, and began moving his army through the mountains into the Hinterlands with the help of the newly-recruited Amani guides, and then into Quel'Thalas. Upon reaching the borders of the elven kingdom, Doomhammer's casters found themselves weakened: his death knights and Amani witch doctors were unable to use their magic inside elven borders. Cho'gall and Gul'dan found out that this was because the elves had a magical barrier that dampened their enemies' spellcasting powers, called Ban'dinoriel, and that the source of this barrier was mystic runestones. Upon destroying enough runestones, the Horde continued its march into Quel'Thalas, using the enslaved red dragons to burn elf and tree alike. The dragons took no pleasure in this act and wept tears for every living thing they burned, but given the enslavement of their aspect, they had no choice but to obey.

Zul'jin quickly made his way to Zul'Aman, where his return invigorated the trolls there. He promised them that the time for revenge had come, and that the elves would surely fall this time around. The Amani, with boosted morale, stormed out of their city and joined the Horde, their brutality and numbers never before seen by the elves.

Soon enough, the combined Horde and Amani forces made their way to the capital, Silvermoon City. Before they could properly invade it, the elves erected a barrier that kept all attacks at bay. With the city safely shielded, they could discuss their options. Turalyon quickly assumed control of half of the Alliance army and made his way to Quel'Thalas, while Alleria, after reuniting with her sister, Ranger-General Sylvanas Windrunner and her second-in-command, Lor'themar Theron, made for Silvermoon to urge King Anasterian to pledge his forces to the Alliance; he needed little convincing in light of the Amani trolls' resurgent attacks. In the meantime, Doomhammer had begun a full-on siege of the city, attempting to break the magical barrier with whatever weapons he had at his disposal. He eventually grew disinterested with the siege, seeing its futility to the Horde, and withdrew the majority of his army, but leaving the Stormreaver, Twilight's Hammer, and Dragonmaw clans behind to help the Amani with the siege. The Amani trolls refused to break the siege, claiming Doomhammer did not deliver his part of the bargain.

At some point after the beginning of the invasion of Quel'Thalas, a small band of orcs broke off from the main invading force and burned the human community of Blackwood to the ground, killing all of its inhabitants in spite of the valorous defense marshaled by Baron Garithos. His son Othmar was then among the human knights who were fighting to defend the high elven homelands, and he blamed the Thalassian people for his family's death.

Aftermath
The Horde's failure to break through the Silvermoon barrier essentially sealed their failure in Quel'Thalas. Orgrim Doomhammer was quickly fed up with the siege and began marching west, towards Lordaeron's capital. He was forced to depart with the Amani trolls, who, full of vengeance and on the cusp of victory, refused to break the siege. Zul'jin promised Doomhammer that he would join him in Lordaeron after Silvermoon was destroyed, but that would never come to pass.

Doomhammer was frustrated by the trolls' stubbornness, he needed their expertise now more than ever. Gul'dan sensed his fear and frustration and used this opportunity to take the Stormreaver clan, on the promise of having found a key to breaking the Silvermoon siege, to the Tomb of Sargeras. This was a ruse, as Gul'dan had planned to abandon the Horde long ago and simply seized the opportunity as it presented itself.

Using the power of the runestones, Gul'dan and Cho'gall were able to reshape the stones they captured into Altars of Storms, and used the powers of the altars to empower regular ogres to become ogre magi. The ogres' arcane prowess was crucial in the campaign in Quel'Thalas and a welcome boon to the Horde. In addition, the Dragonmaw clan were finally able to subdue the red dragons they enslaved, and their true power showed during Quel'Thalas, Doomhammer was eager to test his new weapons on the Alliance, knowing that in Hillsbrad both forces were evenly matched, he felt the Horde was at an advantage now.

The siege of Silvermoon would eventually be lifted when Doomhammer ordered the clans left behind in Quel'Thalas to regroup to besiege Capital City. Only the Dragonmaw clan would arrive, informing Doomhammer that Gul'dan and Cho'gall had betrayed him and abandoned the Horde. The Amani trolls would be unable to hold the siege as the elves began to retaliate. After several costly battles, Quel'Thalas would be restored and the Amani forced back into Zul'Aman. Zul'jin himself was cornered and apprehended by Halduron Brightwing and Lady Liadrin, but the rangers had hoped to keep him alive and drag him to Silvermoon to answer for his crimes rather than execute him immediately. This proved short-sighted, as an Amani war-band raided the elves' camp and caused enough havoc for their captured leader to flee. King Anasterian would withdraw from the Alliance after the war, accusing them of abandoning Quel'Thalas, a controversial stance among high elves even today.

Forces

 * Alliance of Lordaeron
 * Footmen
 * Archers
 * Rangers
 * Knights
 * Paladins
 * Ballistae
 * Mages
 * Demolition Squads
 * Flying machines


 * Orcish Horde
 * Grunts
 * Axethrowers
 * Berserkers
 * Ogres
 * Ogre magi
 * Catapults
 * Death knights
 * Sappers
 * Zeppelins