In the First Age during the War of the Jewels, Dorbon was one of Morgoth's strongest servants. He was originally a Maia of Aule, and his name was Maladhros, but Mairon, another Maia of Aule persuaded Dorbon to join with Morgoth, and so he followed Mairon into the path of darkness. Mairon was like a brother to Dorbon. When Mairon came into the service of Morgoth he was renamed Sauron. During the War of Wrath at the end of the First Age, when Morgoth was finally captured and cast into the Void, Dorbon made the foolish mistake of standing up to the Valar all by himself even when Morgoth was captured and Angband destroyed. Dorbon's final efforts were in vain, for the Valar swept him up and carried him off to Aman as a prisoner along with Morgoth and a few other of his lesser servants. Sauron was more clever than Dorbon, because Sauron fled into distant lands as soon as the first of the servants of the Valar arrived in Middle-Earth. Sauron, unlike Dorbon, knew that he could not face the Valar by himself. When Dorbon had been brought back to Aman and placed before the Valar to be judged, it was deemed that he would not be cast into the Void like Morgoth but would instead be rendered useless and shamed as an Ainur should not be. Therefore, Dorbon was tortured until he was hardly recognisable, then the Valar had the power sucked from his very soul. They had Dorbon paraded around the streets of Valmar to increase his shame. Finally, the Valar had his memory wiped from his mind and Dorbon forgot all that had happened and even that he was a Maia. In fact, from now on, he thought he was an Orc, and he certainly looked like one. Then the Valar cast him back into Middle-Earth where he wandered for thousands of years as an Orc, serving a few masters throughout history. All through the Second and Third Ages Dorbon was in Orc form, and did not know who he was. Even though Dorbon looked as an Orc, others still sensed power in him they could not understand, and he seemed mysterious to those who peered into the depths of his mind. Of course, even Dorbon himself did not know the truth, and in his days as an Orc he named himself Gulgos, and was a big Orc, a great warrior. He served a few dark lords over the centuries as an Orc. Sauron. The Witch King of Angmar. Saruman.
At the end of the Third Age, when the War of the Ring was won by Gondor and Sauron was defeated, Dorbon (or Gulgos as he was then called), was an Orc commander in the service of Sauron. Sauron knew who Gulgos really was, though he did not reveal it. Sauron sensed an inner power in Gulgos, and recognised who he really was, even though Gulgos did not know himself. Sauron did not utter a word though, because he feared that Dorbon could overthrow him if he discovered his old power. Sauron did not know that the Valar had drained Dorbon's power, so even if Dorbon were to discover who he was he would still be powerless. When the One Ring was destroyed in Mount Doom and Sauron was defeated and reduced to a vile spirit in the shadows, Sauron fled into the East. Gulgos did not know why, but he felt love for Sauron. Deep inside, Dorbon's spirit but not his mind remembered the friendship he had shared with Sauron in days of old, even before they had been in the service of Morgoth. In those times Dorbon and Sauron were named Maladhros and Mairon. So, Gulgos followed Sauron out of Mordor and into the East, seeking out his master. He came upon Sauron dwelling as a spirit that haunted the mountain passes in a distant mountain range of the East called the Stony Mountains. There Sauron revealed to Gulgos that he was actually a Maia that had been cursed by the Valar and turned into an Orc. His old name was Dorbon. His true name was Maladhros. The Valar had drained his power and made him into a mere Orc. With the little remaining power that Sauron had, he cleared the mind of Dorbon and filled him again with the power of a true and uncursed Maia. At that day, Sauron had finally repented of his evil ways, and had regretted all that he had done throughout the Ages. Then, Sauron told Dorbon that he must repent and go out again into the world, but try to make it a better place. Dorbon accepted and repented of his evil ways. Sauron wished to have mercy from the Valar, but instead he used his last power to replenish Dorbon, and then his spirit faded to nothingness. Dorbon was left standing there in an empty and lonely cave, and he wept, for he had loved Sauron. Then Dorbon cried out a curse to Morgoth who had caused this world to decay, and had dragged others down with him. Dorbon left the stony Mountains, and he travelled far and wide. But alas, even though Dorbon had repented of his old ways he again fell back into hunger for dominion and control over lands. Slowly, he again became evil and followed the ways of darkness. Eventually, Dorbon took lands under his control and became a dark lord, with great armies and wide dominions. Dorbon renamed himself Cerondur, for the old times were gone. He dared never to go back into the far West of Middle-Earth, there is where the Reunited Kingdoms lived on, and the glory and blood of Numenor is still too strong in the Kings of that realm. But, ever the memory and guilt of his last words to Sauron pained Dorbon's heart.