The Lord of the Rings started with a dramatic introduction as Galadriel narrated a brief history of Sauron’s evils. From there, the whole trilogy was focused on destroying the One Ring and keeping it away from the Dark Lord. As Galadriel said, if he obtained his dominating piece of jewelry, he would have been able to cover all of Middle-earth in darkness.
All of that made Sauron seem like the ultimate big bad, and he was during that time in Middle-earth’s history. However, in the depths of time, there was a villain who was far worse than Sauron. In fact, during the First Age, Sauron was only the lieutenant and servant of Morgoth. Here’s a quick look at the original Dark Lord of Middle-earth.
Everything began with the Eru Ilúvatar creating angelic beings called the Ainur with his thoughts. Together, they sang “Music of the Ainur,” and in doing so, they created Arda and Eä -- the “world and all that is.” Then, Eru took a hands-off approach and allowed the greatest of the Ainur -- the Valar -- to shape Arda as they saw fit.
For a while, everything worked in harmony, but it wasn’t long before one of the Valar began to sow the seeds of discord. Melkor -- the greatest of the Valar -- wanted to create of his own accord but could not part from the power of Eru. He was rebuked for his contentious actions but didn’t learn. When the Valar chose another, weaker Valar as their leader, Melkor had enough. He wanted revenge, so he set out to corrupt everything that the Valar created in Aman.
Along with the Valar, there were also Maiar, who were lesser Ainur in Arda. They became a target for Melkor’s evil, and he drew many of them to his cause. One of the Maia was Ungoliant, another was Sauron and many were Balrogs. Melkor also corrupted elves into orcs and ents into trolls while also creating werewolves and dragons. Melkor built his strongholds in Middle-earth and, with his monstrous horde, waged many wars against the elves of Middle earth. He also committed countless evils against the Valar. He destroyed the Lamps of Middle-earth and stole the Silmarils from Valinor, thus gaining the name of Morgoth.
After the 590 years that comprised the First Age of Middle-earth, the Valar decided to put an end to Morgoth’s evils. What commenced was the War of Wrath -- a massive conflict between the host of Valinor, the elves of Middle-earth and Morgoth’s forces. In that final battle, the combined power of the Valar and the elves were too much for Morgoth. He was overthrown, subdued and cast through the Door of Night into the Timeless Void.
During that time, Sauron was Morgoth’s lieutenant, and he was able to disappear and remain in Middle-earth, setting up the events of The Lord of the Rings. However, the mere fact that the Valar didn’t prioritize perusing Sauron proved he was a much lesser threat than Morgoth. It made perfect sense because Morgoth was a Valar, and Sauron was only a Maia. So, while Sauron was evil, Morgoth was clearly much worse.