With the absence of trolls in the northlands, the elves of Quel'Thalas bent their efforts towards rebuilding their glorious homeland. The victorious armies of Arathor returned home to southlands of Strom.
The human society of Arathor grew and prospered, yet Thoradin, fearful that his kingdom would splinter apart if it overextended itself, maintained that Strom was the center of the Arathorian empire. After many peaceful years of growth and commerce, mighty Thoradin departed on one final quest, never to return, leaving Arathor's younger generation free to expand the empire beyond the lands of Strom.
The original hundred magi, who were tutored in the ways of magic by the elves, expanded their powers and studied the mystic disciplines of spell-weaving in much greater detail. These magi, initially chosen for their strong wills and noble spirits, had always practiced their magic with care and responsibility; however, they passed their secrets and powers onto a newer generation that had no concept of the rigors of war or the necessity for self-restraint.
These younger magicians began to practice magic for personal gain rather than out of any responsibility towards their fellows.
As the empire grew and expanded into new lands, the young magicians also spread out into the southlands. Wielding their mystical powers, the magicians protected their brethren from the wild creatures of the land and made it possible for new city-states to be constructed in the wilderness. Yet, as their powers grew, the magicians became ever more conceited and isolated from the rest of society.
The second Arathorian city-state of Dalaran was founded in the lands north of Strom. Many fledgling wizards left the restraining confines of Strom behind and traveled to Dalaran, where they hoped to use their new powers with greater freedom. These magicians used their skills to build up the enchanted spires of Dalaran and reveled in the pursuit of their studies.
The citizens of Dalaran tolerated the magicians' endeavors and built up a bustling economy under the protection of their magic-using defenders. Yet, as more and more magicians practiced their arts, the fabric of reality around Dalaran began to weaken and tear.
The sinister agents of the Burning Legion, who had been banished when the Well of Eternity collapsed, were lured back into the world by the heedless spellcasting of the magicians of Dalaran. Though these relatively weak demons did not appear in force, they did sew considerable confusion and chaos within the streets of Dalaran.
Most of these demonic encounters were isolated events, and the ruling Magocrats did what they could to keep such events hidden from the public. The most powerful magicians were sent to capture the elusive demons, but they often found themselves hopelessly outmatched by the lone agents of the mighty Legion.
After a few months the superstitious peasantry began to suspect that their sorcerous rulers were hiding something terrible from them. Rumors of revolution began to sweep through the streets of Dalaran as the paranoid citizenry questioned the motives and practices of the magicians they had once admired. The Magocrats, fearing that the peasants would revolt and that Strom would take action against them, turned to the only group they felt would understand their particular problem: the elves.
Upon hearing the Magocrats' news of demonic activity in Dalaran, the elves quickly dispatched their mightiest wizards to the human lands. The elven wizards studied the energy currents in Dalaran and made detailed reports of all demonic activity that they beheld. They concluded that although there were only a few demons loose in the world, the Legion itself would remain a dire threat so long as humans continued to wield the forces of magic.
The Council of Silvermoon, which ruled over the elves of Quel'Thalas, entered into a secret pact with the Magocrat lords of Dalaran. The elves told the Magocrats about the history of ancient Kalimdor and of the Burning Legion, a history which still threatened the world. They informed the humans that so long as they used magic, they would need to protect their citizenry from the malicious agents of the Legion.
The Magocrats proposed the notion of empowering a single mortal champion who would utilize their powers in order to fight a never-ending secret war against the Legion. It was stressed that the majority of mankind could never know about the Guardians or the threat of the Legion for fear that they would riot in fear and paranoia. The elves agreed to the proposal and founded a secret society that would watch over the selection of the Guardian and help to stem the rise of chaos in the world.
The society held its secret meetings in the shadowed Tirisfal Glades, where the high elves had first settled in Lordaeron. Thus, they named the secret sect the Guardians of Tirisfal. The mortal champions who were chosen to be Guardians were imbued with incredible powers of both elven and human magic. Though there would only ever be one Guardian at a time, they held such vast power that they could single-handedly fight back the Legion's agents wherever they were found in the world.
The Guardian power was so great that only the Council of Tirisfal was allowed to choose potential successors to the mantle of Guardianship. Whenever a Guardian grew too old, or wearied of the secret war against chaos, the Council chose a new champion, and under controlled conditions, formally channeled the Guardian power into its new agent.
As the generations passed, Guardians defended the masses of humanity from the invisible threat of the Burning Legion throughout the lands of Arathor and Quel'Thalas. Arathor grew and prospered while the use of magic spread throughout the empire. Meanwhile, the Guardians kept careful watch for signs of demonic activity.