The War for Stormwind's Independence was a great civil conflict between the Arathorian Empire and the Stormwind Militia that resulted in the founding of the Kingdom of Azeroth and the expulsion of the Arathorian Legion from continental Azeroth.
Settlement of Azeroth
When a number of nobles of the Arathorian Empire made their exodus to the verdant lands south of Khaz Modan nearly 900 years ago after the onslaught of the religious civil war that left Lordaeron, Kul Tiras and Gilneas independent and the empire in dire need of colonial outlet, they brought with them a contingent of Arathorian Legionnaires of to clear the land and assist in constructing the fledgeling colony of Azeroth - led by the descendants of Thoradin, the ancestors of Lord Anduin Lothar
The Arathorian Legion encountered several native human clans in the forests of Azeroth, whom initially welcomed the soldiers in appreciation for their subjugation of the gnoll and murloc tribes. Of fair skin and hair, the native humans of Azeroth maintained a culture of martial prowess and family duty. Such was absorbed into the colonial efforts of the Arathorian Legion, where Legionnares intermarried with the local population and the people of Azeroth took on Arathorian customs.
As time passed, the colony became a key source raw materials. Present day Elwynn, Redridge, Westfall, and Duskwood were settled and developed, their verdant pastures and rich mountains yielding grain and iron in vast quantities. Thus the colony of Azeroth supported both its hardy colonists and the needs of distant Arathor. Stormwind City was constructed as Arathor's primary base of power in the region, its ports bustling with the trade and military vessels that shipped Azeroth's goods to the far-flung reaches of the empire.
Tensions with the Empire
After nearly three centuries of semi-autonomy, internal strains on the empire brought about a heavy burden on the colony. Overpopulation and drought in Arathor drove the Emperor Tyban II to demand almost all of Azeroth's goods, sending in an additional legion of soldiers under the command of Legate Lennitus Condriga to take by force what he demanded - leaving most of the people of Stormwind impoverished and resentful towards the empire.
Massacre at Lakeshire and the Stormwind Militia
Sources vary as to who dealt the first attack of the war of independence, but the most accepted claim is that legionnaires under the command of Legate Condriga executed nearly one hundred protesting frontier colonists in present day Lakeshire to make an example of the empire's sovereignty in January of 6 P.C. This act was named the Culling of Lakeshire, and was used as a rallying cry for those who protested Arathorian rule. Almost immediately after the demonstration, local militias sprung up and took up arms against the Arathorian Legion.
Logan Wrynn I, an influential Azeroth-born lord from the Northern Elwynn Mountains, rallied an effective militia army comprised of colonists and Arathorian deserters, which came to be known as the Stormwind Militia. The gathered militia laid siege to Stormwind City before the legionnaires of the colony could adequately respond, setting fire to its structures - then fleeing into the countryside as Arathorian reinforcements arrived.
Open war broke out across the countryside of Azeroth. The forces of the Stormwind Militia suffered defeat after defeat against the well-trained legionnaires, pushed out of the colony's capital and into the heartlands - the Arathorian Navy effectively keeping the legionnaires supplied in their spread across the land.
Attrition in the Forests
Forced onto the defensive, Lord Logan withdrew his forces into the wilds of Elwynn Forest and Brightwood, spiriting away to isolated camps. Legate Condriga gave pursuit, but ultimately lost the militia in the thick forests. He sent out wave after wave of Legionnaires into the wilds in attempt to capture Lord Logan. Most, unaccustomed to warfare in the thick forests, were torn apart by ambushes and well-placed traps.
For months, Lord Logan bided his time - reviewing strategy with his Generals and sending agents to secretly secure the support of other Lords or their servants throughout the Azerothian colony. A number of Arathorian soldiers deserted to the militia's cause, and it was not long before the Stormwind Militia could not easily hide due to its growth.
The Great Rebellion
Believing his forces ready to take on the legion, Lord Logan's called to war all who he had sought support from throughout Azeroth - fielding his army openly as a number of the Arathorian Legion's garrisons were overthrown by rebels loyal to the militia's cause. The garrisons at Westridge, Westfall and Lakeshire were swiftly overrun and destroyed, its legionnaires withdrawing and joining the bulk of the remaining empire loyalists. Faced by chaos, Legate Condriga imposed brutal martial law upon the remaining holdings of the empire, which included the Red Steppes, Stormwind City, and central Elwynn Forest.
Lord Logan issued a challenge to Legate Condriga for their armies to meet in battle in eastern Elwynn - a call that the Legate took in earnest, bringing to bear the might of a freshly resupplied legion of troops in disciplined formation. Clashing in what is present day Eastvale, the undisciplined ranks of the Stomwind Militia were crushed in the field - fighting a battle that favored the closed ranks of the legion.
Battle of the Three Corners
All would have been lost if not for the second front that opened against the Arathorian Empire. Kul Tiras, a nation bitterly rivaling and coveting the Arathorian Empire's naval dominance, upon hearing of the conflicts in Azeroth, prepared its fleets for an attack on the Arathorian homeland. Launching an attack by sea on the empire's capital while the rest of the Arathorian forces were occupied in Azeroth, Kul Tiras effectively cut off reinforcements bound for the colony.
When word reached Azeroth of the assault on Arathor, Legate Condriga made a mistake that would cost him the war. Confident that his legion would be able to defeat the weakened Stormwind Militia without reinforcement or supply by sea, the ground forces remained while the Arathorian fleet made haste for the battle that raged on Strom's coast.
Facing annihilation, the Stormwind Militia had retreated into the Redridge Mountaints. Instead of withdrawing to Lakeshire and its garrison, Lord Logan ordered the Stormwind Militia to meet the legion at the 'Three Corners,' constructing barricades and that would prevent the legion from making use of their superior numbers in crossing the mountain rivers. Shield walls clashed and blood spilled freely, giving the mountains their namesake - "Redridge." After days of fighting, the order was given for the Arathorian Legion to break off of the attack and retreat to Stormwind Harbor.
Siege of Stormwind City and Independence
Harassed by guerrilla fighters and the army that followed them from Redridge, the legion was in shambles by the time it made it to the city gates. When they passed through, however, they found their navy embattled with the Kul Tiran fleet, having itself retreated from a rout off the coast of Strom. The Stormwind Militia pushed the Arathorians to the very harbor, where Legate Condriga fell in battle. Surrounded and with no choice but to surrender, the forces of Arathor granted victory to the Stormwind Militia and Kul Tiras - the latter sailing home, satisfied after having crushed the divided navy of Arathor.
Such began The King's Calendar, the year in which Azeroth declared itself its own sovereign nation apart from the Arathorian Empire. Lord Logan Wrynn I was named King of Azeroth, the various estates of the kingdom divided up amongst the nobles who supported the independence efforts. King Logan was merciful in dealing with the nobles and surviving loyalists to the empire. He allowed many to keep their lands if they swore fealty to his new kingdom. The few who did not were given safe passage back to Arathor, allowed to take with them their personal effects. In a motion that shocked many, the direct descendants of the House of Thoradin swore fealty to the king, solidifying his legitimacy among the Eastern Kingdoms.