Medivh lived his early childhood happily in the King’s court with Anduin Lothar, and Llane Wrynn because his father, Nielas Aran, was the court conjurer. The three friends became inseparable, having several adventures together, and they were witness to Medivh's budding mage powers.
Soon after, on his 14th birthday, Medivh awoke from a nightmare where he ran from shadowy figures through a dark chasm. Going to his father’s room for comfort his latent power awoke when Aran touched his sweaty brow. The surge of his mother’s power was so great that it took 100 clerics to contain it and keep him alive, but his father did not survive.
For 20 years Medivh lay in a coma, Sargeras working to enslave his body and mind. Llane and Lothar stayed by his side, tending to him and watching over him all those years. Lothar even remarked to Medivh’s apprentice later, that he remembered seeing a shadow watching over Medivh as well, but thought at the time that it was a trick of the light and long hours spent by his bedside.
When Medivh finally awoke he was a grown man. He had lost his childhood. And he was the Guardian. Sargeras preyed on his negative feelings, amplifying the unfairness of being saddled with the responsibility of the Protector of Azeroth against the demons with no say in it. In losing his youth, missing out on all the normal stages of growing up, and friends. He was awkward, abrupt and curt with all but his closest friends, and trusted no one.
Sargeras allowed him only a small part of his life, using him to deceive the king and his friends. Whenever he was odd, or eccentric, they chalked it up the the nature of his job, the stress he was under, and the power of the Guardian.
At that time, the biggest threat to the human capitol was the Gurubashi trolls, but Llane’s father, King Barathen, was not interested in fighting an aggressive war against them, only wanting to protect his lands, and he felt pretty safe behind Stormwind’s walls. However his son and future Champion (Lothar) felt quite differently, partly because they were young and looking for something to fight and partly because the residents of towns such as Westwood, outside of Stormwind, were not protected from the trolls’ vicious attacks and suffered greatly. They pressed the King to do more to push the trolls back, and when he refused, went off on their own to see what they could accomplish.
The three friends Prince Llane Wrynn, Medivh and Anduin Lothar infiltrated Stranglethorn with the intent of quickly killing Jok'non in his ziggurat and then retreating, leaving the trolls without a leader. However, their plan was anything but flawless. When battle erupted, it attracted a tremendous amount of attention, and the three humans soon found themselves in a brutal fight for their lives. Medivh dueled Jok'non himself, facing a breed of magic he had never seen. Jok'non's dark power nearly overwhelmed Medivh, forcing the Guardian to abandon his apprehensions and unleash his full might. The resulting spell destroyed every single troll inside the ziggurat, and their howls of agony were heard throughout Stranglethorn.
The three men hurried back to Stormwind, but there was no joy in their victory, for they had witnessed Medivh's dark side and realized that their old friend was different in ways they could never understand. Medivh himself did not fully understand what he had done and had no idea where the knowledge to cast the destructive spell had come from or if it had been entirely powered by arcane magic. It disturbed him greatly.
Though none of the trolls who had witnessed Warlord Jok'non's death survived, it took little imagination for them to guess who was responsible, and the Gurubashi soon rallied under Jok'non's son, Zan'non, and marched against Stormwind, beginning the Gurubashi War.
While none of the Gurubashi who witnessed Jok'non's death survived, it took very to the imagination for the trolls to see who was responsible. Rallying under Jok'non's son, Zan'non, the Gurubashi launched an invasion intent on destroying Stormwind. In the face of the troll onslaught Barathen recalled all his forces to the stronghold's gate, believing that the survival of Stormwind would depend on one colossal battle. As the death toll mounted on both sides Barathen mounted a desperate counterattack against the Gurubashi. Though almost succeeding in claiming Zan'non's head, Barathen would die on the field of battle. Llane, driven by guilt, would plead with Medivh to unleash his power on the Gurubashi as he done against Jok'non. Though frightened of his power Medivh would accept Llane's request and destroy the Gurubashi forces (Zan'non included), an act that would ultimate avenge Barathen. With his father's death and the victory over the Gurubashi, Llane would be welcomed as Stormwind's new ruler.
The Kirin Tor, seeking to discover more about this elusive and powerful mage, sent him many apprentices. Most either gave up and left within the week or disappeared and were never heard from again. Until Khadgar. Something about the young, earnest mage appealed to the part of Medivh that was still human. Khadgar’s name, in old dwarfish, means trust. And that is what Medivh called him, “young Trust”. Most of what we know about Medivh comes through the eyes of his young assistant. He was set to organise Medivh’s great library, as a test of sorts, and when he was not dead a week later, Medivh took him under his wing and began to involve him more closely in his own affairs. Khadgar saw what a great weight was placed on the magus, and how it drained him. How he was constantly being asked to provide help all over the continent and how the Kirin Tor feared him and was in awe of him at the same time. The existence of The Guardian was a secret known only to a few, and Medivh received coded missives from the secret members of Tirisfal, keeping him informed of what was happening in all the lands they traveled.
This is when Khadgar started seeing the visions.
Karazhan tower is special. Aegwynn built it in a place called Deadwind Pass for a very specific reason. Thousands of years before Medivh came to live there, Satiel, an eredar in the service of the Burning Legion, attacked all the people living in the area in order to prepare it for the coming of Sargeras. She wielded the Legendary artifact Ulthalesh, the Deadwind harvester. Get the name now? The scythe drained the souls from everyone living there and then drained the very land of all vitality. It took a land verdant with trees and wildlife and turned it into an ashy grey landscape where nothing breathed. When she swung the scythe it dug a great crater in the side of the land and tore a hole in the very fabric of reality, opening a kind of portal to a torrent of magical energy. Satiel did not survive, but much, much later, Aegwynn built Karazhan on top of that nexus of ley lines and magical power.
One of the side-effects of Karazhan, being built where is was, were the visions, and the ghosts. People who came to Karazhan, weather to visit, to rob the place or to discover its secrets, were trapped within its walls. Like the souls trapped within Ulthalesh. If you died there, you could never leave. Spectral butlers, spirits of party guests and even actors and actresses could be seen practicing their roles for all of eternity. And not all the spirits were friendly.
Then there were the visions. The hole in the fabric of reality messed with time, and many people became lost in visions of the past or far flung future (this explains why many of Medivh’s assistants did not last long).
Khadgar began to see visions of Medivh’s past, and his own future, and eventually, as he became more in control of his own power, he started controlling the visions in a fashion, though the results were often unpredictable, and he asked to see certain things.
One of the first visions he saw was of himself as an old man, fighting strange green abominations in a world with a red sky (the orcs on Draenor). When he told Medivh what he had seen, the mage was surprised as it was not a future he was aware of. He was however very aware of the ability of Karazhan to show visions and told Khadgar that they were always true.
Shortly after this Medivh took Khadgar with him on a visit to Stormwind, where he had been called to investigate the deaths of two of the strongest mages in the city. When they arrived and investigated the crime scene, it appeared that the two men had summoned a demon, lost control of it, and were burned alive by its magic. There were a couple things not quite right with the scene, but when Khadgar brought his suspicions to Medivh, the magus grew angry and impatient, talking him down. Medivh soon went off alone into the city to search for the demon, who was still at large, and later returned, exhausted, with its head.
When Khadgar and Medivh return to Karazhan, Medivh had to rest for several weeks, his fight with the demon apparently draining him greatly. And as Khadgar watched over his rest, he too saw the shadow of Sargeras, appearing over Medivh’s bed.
Although he trusted Medivh, and did not want to think badly of him, Khadgar started to suspect that there was more to Medivh’s eccentric ways, than even Lothar and Llane were willing to admit, and he started to investigate. He ran into Garona Halforcen, whom Medivh called, The Emissary, and they both investigated Medivh together. Garona had been meeting with Medivh in secret for a while, the go-in between sent from the Gul’dan, and she trusted him as well, being treated better by him than any orc or human that she had met. Their investigations into the visions that the tower could provide eventually proved that Medivh was the one who had appeared to Guldan on Draenor, that he had given the orc instructions to build the portal that would bring them to Azeroth, and the promise, not only of a weak land, ripe for the taking and conquering, but also the location of Sargeras’ body, who Guldan worked for, so he could raise him. Further they saw a vision where Aegwynn confronted Medivh and asked him what his purpose was in creating the portals that led the orcs to their world. As his mother she was attuned to the signature of his magic and it didn't take her long to figure out he was the one responsible. In the argument that ensued, the real truth came to light. Sargeras revealed himself. He had not been killed by her as she had previously supposed, but infected her like a virus, binding himself to Medivh while he was still in her womb. She was horrified and raised her hand to strike him down with her magic. Sargeras could not defeat her, Medivh still had enough control over his body that he would not allow the killing of his own mother, so he banished her far away so that by the time she was able to make her way back, his plan would be advanced beyond her ability to stop him.
Immediately Garona and Khadgar fled to warn Llane and Lothar of their friends betrayal. Llane could not believe that Medivh did not have something else up his sleeve, that everything was not part of a bigger picture that they could not see yet. But Lothar knew, he took some men and went with Garona and Khadgar back to Karazhan, and together they fought Medivh and Sargeras. Khadgar struck the killing blow, stabbing Medivh through the chest with a Guardsman's sword, and when Sargeras started to take over and transform, Lothar cut his head off. Finally Medivh was free. His last words were “Thank you, I held on for as long as I could.”