When the world of Azeroth was still new, the Titans created what became known as the Well of Eternity, a seemingly infinite fount of power and magic for the planet. After some time, a tribe of dark trolls settled on the banks of this well, where the power emanating from the waters of the well eventually transformed them – changing their skin to various shades of purple and violet; their backs straightened as they grew taller, and they became stronger and, eventually, immortal.
They began to worship the moon goddess Elune, believing that she slept in the depths of the Well during the day, and began calling themselves the Kaldorei, or “Children of the Stars.” While they worshiped the goddess, the Kaldorei studied the Well of Eternity, curious to learn all they could about the secrets of the Well. As their knowledge grew, so did their empire. It rapidly expanded across Kalimdor with the help of magical powers and knowledge that the Night Elves had gained from the depths of the Well, powers that their adversaries – the trolls of the Amani and Gurubashi tribes – could not have fathomed. By systematically destroying all supply chains and dismantling the defenses of the trolls, the Night Elves managed to fragment the two great empires within a few short years. To this day, the animosity between the two races (which has also stretched to include the blood elves) can still be felt.
While their knowledge and newfound power gained them eternal animosity of the Trolls, it also brought on the alliance of the demi-god Cenarius, who made his home in the forests. He grew fond of the new race and their curiosities, and eventually taught them to live in closer harmony with the natural world around them, bringing a strong empathy between the race and their environment. The most notable race, though, that they did not ally with was the dragons. Often reclusive, the Night Elves came to believe that they were the guardians of Kalimdor, and went out of their way to ensure that the dragons secrets stayed their own.
As time went on, the Kaldorei empire and civilization blossomed and grew and their temples, roads and towns began to flourish. One city in particular, built by the queen of the empire, Azshara, flourished, and became even more grand than any others. She built a palace along the shores of the Well of Eternity, housing her personal favorites among the Night Elves, naming them “Quel’dorei,” or “Highborne.” She shared the insatiable curiosity of the priests and her chosen few about what the depths of the Well held, and ordered her most devout followers to learn and reveal its true purpose in the world. In time, this ceaseless study and work for the knowledge of the Well lead them to develop the ability to manipulate the energies of the Well, to either create or destroy without consequence. While they cautioned themselves and others that the magical abilities were dangerous if handled improperly, they themselves began to practice with reckless abandon. Ignoring the words of caution from Cenarius and some of their own scholars that to abuse such magics would only bring about ruin and calamity, Azshara and her faithful followers continued to expand upon their powers and exercise them without caution.