Designation: High elf
A descendant of Dath'Remar Sunstrider, King Anasterian ruled the high elves during the latter part of the Troll Wars, when defeat began to seem inevitable. Greatly outnumbered, the elves were losing ground, and the outlook worsened every day as their casualties climbed. Even their most powerful magics were of little use.
Strange Alliance
Anasterian hit upon a radical idea. His scouts had reported that a human nation named Arathor had recently formed to the south. One tribe had risen to dominance through the simple expedient of offering amnesty to the people it defeated. That such a strategy was new among humans was a testament not only to the youth of their race, but also to their willingness to gain strength via clear-sighted pragmatism.
Although the humans had no spellcasters, Arathor had a sizeable population. Anasterian was certain there had to be humans with magical talent. They merely needed training in order to be useful in combat. He therefore dispatched ambassadors to the southlands with all speed.
King Thoradin of Arathor greeted the ambassadors with surprise and wary courtesy. He had been hearing rumors of the high elves' plight for months, but he had not suspected that the trolls posed a truly significant threat. The weary elves warned the king that the troll armies were vast. Should Quel'Thalas fall, the trolls would certainly besiege Arathor next.
The king was distrustful of magic, but he could not deny that the elves had a point. Further negotiations ensued until at last Anasterian and Thoradin had reached an agreement. Almost immediately, elven sorcerers arrived in Arathor and began to instruct a group of humans in the ways of magic. One hundred men were taught the very basics of the elves' magical secrets: no more than was absolutely necessary to combat the trolls.
In addition to these new spellcasters, Thoradin sent his armies to the battlefront. Together, the humans and high elves ultimately achieved victory over the trolls, who would never fully recover from their defeat. Assured that Quel'Thalas was saved from destruction, the elves made a pledge of loyalty and friendship to the nation of Arathor and to the bloodline of King Thoradin. Humans and elves would coexist in peace for over two thousand years.
Conflict in the Borderlands
When the Horde attacked humanity in the Second War, the high elves had little interest in the conflict, but they felt duty-bound to lend the Alliance of Lordaeron their support. In particular, the commander of the Alliance forces was Lord Anduin Lothar, who was the last descendent of the Arathi bloodline. Lothar's family had aided the high elves in fighting the Troll Wars, and so King Anasterian reluctantly agreed to provide a small number of soldiers and spellcasters who would fight alongside the Alliance.
The king and his people would soon see the conflict in a more personal light. Horde forces worked their way north, burned down the borderlands of Quel'Thalas, and slaughtered many high elves. Horrified at the Horde's wanton destruction of life, the high elves officially joined the Alliance and committed all their resources to the war. Ultimately the orcs were defeated, and most of them were rounded up and put into internment camps.
Downward Spiral
In the aftermath of the war, the high elves began to doubt the value of the Alliance. Humanity seemed to need the high elves, but had little to offer in return, especially now that a large portion of Alliance resources was allotted toward maintaining the internment camps.
At last Anasterian rescinded the high elves' allegiance to the Alliance. He stated that the humans' poor leadership had been directly responsible for the burned forests in the borderlands of Quel'Thalas. King Terenas Menethil argued that nothing of Quel'Thalas would have survived if not for the hundreds of valiant humans who gave their lives to defend it. Despite his attempts at reestablishing diplomatic relations, however, the elves opted to remain independent of the crumbling Alliance. Their departure triggered the additional secession of the Gilneas and Stromgarde nations.
Anasterian was still in power years later when the death knight Arthas Menethil led Scourge forces into Quel'Thalas and defiled the Sunwell. The king and most of his people were slain in battle by the undead. His son, Prince Kael'thas Sunstrider, was in Dalaran at the time of the invasion, and so Kael'thas is the last surviving member of the royal family.