Part of what defines a great hero is the caliber of their villains. Who would Batman or Superman be without the Joker or Lex Luthor? Every champion needs to be challenged and for Hal Jordan, there is no greater foe than Sinestro.

Thaal Sinestro has served as a foil for Hal Jordan almost from the beginning of the Green Lantern’s journey. In many ways, he has always been a dark reflection of Hal. He has not only become Jordan’s greatest foe, but the entire Green Lantern Corps' as well. He even formed his own Sinestro Corps to combat them.

Sinestro has become more than a mere villain, though. He is an extremely complex character who began as two-dimensional, but over the years has become multi-faceted. The man has gone from hero to villain to anti-hero and along the way, has become one of the most fascinating figures in DC Comics. Here are 15 Things You Didn’t Know About Sinestro.

15. He was created by comic book legends Gil Kane & John Broome in 1961

This is the same team-up that brought us Sinestro’s arch nemesis, Hal Jordan. While John Broome and Julian Schwartz had already thought of the ideas for Green Lantern, it was up to Gil Kane to dream up the overall character designs. Kane, who once lived next door to Paul Newman, based Hal Jordan’s appearance on him. Sinestro, and his mustache in particular, was based on actor David Niven, who starred in such films as The Pink Panther and Casino Royale.

Broome began his career as a science fiction writer, before transitioning to DC Comics. He also went by the pseudonyms John Osgood and Edgar Ray Meritt. Broom made many important contributions to the DC Universe. He co-created several major Flash villains, including Captain Boomerang and Professor Zoom. Aside from that, Broome also introduced readers to Kid Flash and the Elongated Man.

Gil Kane is well known in the comics industry and beloved by fans. His art defined the modern versions of Green Lantern and the Atom. He drew many other titles for DC as well, like Superman and Flash. Those are hardly his only significant contributions though. He was instrumental to Marvel Comics too, co-creating Iron Fist and drawing everything from Daredevil to Iron Man. It was Kane (along with John Romita Sr.) who rendered Amazing Spider-Man #96-98, the first mainstream comic to depict drug use, which famously angered the Comics Code Authority. The storyline led to changes for the code, which in turn, affected the entire industry.

14. He was born on the planet Korugar and used to be an anthropologist

Korugar is a planet in Sector 1417. It was a peaceful place, whose indigenous residents looked much like humans, except for their red skin. Because Thaal Sinestro is what the planet has become known for, little of what it was like before his birth has been shown in comics. One thing we know for sure is that, although Sinestro loved his home world, he would eventually prove its undoing. His profession on Korugar was anthropology. He wanted to study every aspect of his planet, from biology to beliefs.

These brief glimpses into the man he was before corruption took hold of him were not written about until many years after his creation, but serve to give far more depth to the character. Sinestro enjoyed piecing together ancient ruins, which was perhaps an early display of his propensity for order. It was at one of his reconstruction sites that he met his true destiny.

13. He let another Lantern die so that he could take his place

A Green Lantern named Prohl Gosgotha crash-landed on Korugar, pursued by Qwardians. He had the extreme misfortune of being found by Sinestro. The Lantern enlisted the Korugarian to aid him in fighting his enemies. Due to his grievous wounds, Prohl Gosgotha trusted Sinestro with his power ring. The two did indeed defeat their attackers and after their victory, the Green Lantern asked Sinestro to return his ring.

This was an important moment for Sinestro. Obviously, he made the wrong call here or he wouldn’t have gone on to become one of the greatest villains the galaxies had ever seen. He let the Lantern die, despite his pleas for Sinestro to give his ring back. It was this tragic decision that began Sinestro on his villain’s journey. However, before becoming an evildoer, he would wind up being a hero, at least ostensibly. Regardless of the work he would go on to do, it could all be traced back to letting another being die for his own gain.

12. He was once the most respected Green Lantern in the Corps

Sinestro wasn’t always a villain. Despite the questionable circumstances under which he obtained his ring, his Sector, 1417, was nearly completely free of criminal activity while under his watchful eye. During his tenure as a Green Lantern, Sinestro mentored many rookies, including a young hotshot named Hal Jordan. The Guardians had no reason to doubt Sinestro. They’d never been wrong about a Lantern before. This would go down in history as the greatest mistake the Guardians ever made.

Sinestro’s power completely consumed him. The planet Korugar went from being his home to being his kingdom-- and he ruled it with an iron fist. Eventually his citizens rebelled and he was brought to trial on Oa. After bearing witness to Sinestro’s cruelty, Hal testified against him, an act that Sinestro would never forgive him for. As punishment for his crimes, the Guardians banished Sinestro to the Antimatter Universe, where he wound up on the planet Qward.

11. His yellow power ring was forged by the Weaponers of Qward

While Sinestro’s castigation at the hands of the Guardians was just, it also completely backfired on them! Qward had Weaponers and their hatred of the Guardians matched Sinestro’s own. Because of this, they became fast friends. The Weaponers of Qward fashioned him a ring that, while similar to a Green Lantern ring, harnessed yellow energy. It was revealed later that these rings utilize fear, while GL rings are powered by will.

Sinestro’s yellow ring proved particularly useful in fighting Hal Jordan and the other Green Lanterns. Over the years, different GLs have had different weaknesses. For the Golden Age Lantern, Alan Scott, it was wood. For Jordan, it was the color yellow (a fact that he somehow managed to forget every other issue during the Silver Age). Eventually, Jordan was able to overcome this vulnerability, but the color yellow proved to be his kryptonite for quite some time. Thus, Sinestro’s ring proved a powerful weapon against him.

10. His wife was the sister of Abin-Sur, Hal Jordan’s predecessor

The story of how Hal Jordan received his ring is almost a mirror image of the way that Sinestro got his. There is one incredibly important distinction however, which is that Hal did not let his predecessor die to steal his ring. It was later revealed that this alien, Abin Sur, was actually Thaal Sinestro's best friend, and that his late wife, Arin Sur, was Abin Sur's sister.

Although Sinestro has managed to live a life free of emotional entanglements, there is plenty of empirical evidence to suggest that he was very much in love with Arin. It was his own ambition that ultimately killed her and he never got over that. While battling the Star Sapphire Corps, Sinestro was forced to relive losing her over and over. Had he not still loved her, this would not have been torturous at all. Arin and her brother were briefly resurrected during Blackest Night as Black Lanterns. Jordan and Sinestro had to both use their powers to put them back to rest.

9. He has a daughter who also became a Green Lantern

Sinestro and Arin’s marriage yielded a daughter. Arin, who had begun to fear her husband, gave Soranik to friends who would raise and protect her. Soranik Nato’s parentage wasn’t actually revealed until she’d been appearing in comics for a few years. She was initially portrayed as a surgeon and reluctant Lantern on account of the fact that Korugar despised the Corps after Sinestro’s disastrous dictatorship. After becoming a Green Lantern, Soranik brought order to Korugar without becoming a despot and became a true hero.

Eventually, Sinestro made contact with Soranik, revealing himself to be her father. He explained that he had actually been watching her for years, even marking her so that he could always keep track of her (because that’s not creepy at all). It turned out that Sinestro was proud of his daughter’s accomplishments and he expressed that, along with the fact that they would need to work together to stop Blackest Night. Their relationship since then has been complicated, to say the least.

8. Although they imprisoned him, the Guardians released Sinestro to fight Parallax

After the events of DC mega-event Crisis on Infinite Earths, Sinestro was caught and imprisoned by the Guardians in the Central Power Battery. Once inside, he was converted into energy and laid in wait for his moment to strike. Hal Jordan losing his mind proved to be the perfect moment. Once Jordan had run through the entire Corps, the Guardians, in an attempt to save their own skins, released Sinestro. He was their last hope in defeating Parallax, so they reluctantly gave him a power ring.

Sinestro and Jordan fought, Lantern battling Lantern. At a certain point, the rings were out of it and the battle came down to hand-to-hand combat. Sinestro baited Jordan, taunting him in an effort to push him over the edge. It worked, and Jordan, reaching his limits, snapped Sinestro’s neck. This led to Jordan’s rampage, eventual defeat, and death (although, while dead, he returned as the Spectre).

7. He was actually the architect of Hal Jordan’s destruction

For many years following Emerald Twilight, it was believed that Jordan lost his mind after his home, Coast City, was decimated and that that was why he became the villain known as Parallax. While the story was controversial, it was also one of the most humanizing superhero stories ever told. Geoff Johns (indisputably the writer who has had the most input in Hal Jordan's development in the past decade) basically retconned Hal’s entire emotional breakdown in the story that resurrected him, Green Lantern: Rebirth. Johns is an amazing writer and has created many of the finest Green Lantern tales ever committed to paper. However, some saw this move as a copout (although it did explain that whole "yellow weakness" thing).

It turns out that Hal was possessed by the ancient entity Parallax. Being the embodiment of fear, it fed into his own fears, forcing him to commit unforgivable acts. This parasite didn’t choose Jordan as a target on its own though. Parallax had been imprisoned in the Central Battery for billions of years and was awakened by Sinestro’s power ring when they became cellmates. It was Sinestro’s seething hatred of Jordan that actually caused Parallax to choose the Green Lantern as his next victim. Thus, while it was thought for quite some time that Jordan was his own worst enemy, it was Sinestro, Jordan’s true nemesis, that caused his fall from grace.

6. He has cheated death more than once

Jordan snapping Sinestro’s neck didn’t actually kill him. It was later revealed that it wasn’t even Sinestro who Hal was battling, but a light construct sent to fight in his stead. The parasite, Parallax, had created the ersatz villain, while the real Sinestro controlled the construct from the safety of the Power Battery. So, when Jordan snapped his neck, Sinestro survived, later popping up to make Green Lantern Kyle Raynor the new source of his animosity.

However, this wasn’t the first time that Sinestro managed to cheat death. Long before this fight, after escaping his imprisonment at the hands of the Guardians, he went on to commit genocide several times over. For these crimes, the Guardians sentenced him to death. They executed him, but not before he managed to transport his essence into the Central Power Battery. Jordan and the rest of the core managed to defeat him, but that's how he became trapped there in the first place.

In the more recent DC Rebirth run, Hal and Sinestro fought a brutal battle, seemingly resulting in both their deaths. We’ll have to wait and see if Sinestro managed to stave off a meeting with his maker once again.

5. He can destroy power rings

Green Lantern rings are some of the most powerful weapons in the universe. They are limited only by the wearer’s will and imagination. They are also supposedly indestructible. While it is true that the rings need to be recharged, their power is still absolute. It is unfathomable that anyone could actually possess the sheer strength of will necessary to actually destroy one of these rings. Well, not only has Sinestro done this, but he’s done it more than once!

During a conversation with Jordan in the New 52 run, Sinestro admits, rather cavalierly, that he has broken a ring through overexertion, not once, but twice. This is a shocking revelation. More than that, though, it is just further evidence that Sinestro is an incredibly gifted Lantern. Had his path not been so completely derailed, he could’ve been known for his gifts and good works, not for his tyranny and destruction.

4. He was given more of an antihero role in the New 52

To truly understand Sinestro, you must first understand that like many villains, he doesn’t consider himself to be one. He truly believes that he was doing only what was required to restore order to the galaxy, beginning with Korugar. Perhaps this is why in the pages of Green Lantern vol 5, Sinestro was cast as an antihero, rather than the monster that he has always been portrayed as. The power ring chooses Sinestro and although the Guardians initially see this as pretty much the worst thing ever, they also understand it as a chance at redemption.

Sinestro not only goes on to attempt to save Korugar by fighting his own Corps, but also enlists Hal’s help in doing so. He also winds up discovering that the Guardians aren’t the force for good that everyone has always thought. Sinestro has had quite an impressive character arc under Geoff Johns, who is essentially the reason that he has gone from a rather arch-villain to an antihero desperately seeking atonement. Of course, because Sinestro still believes that fear is the best way to maintain order in the universe, he and Jordan will continue to be pitted against one another. Ultimately, Sinestro will always be a villain to everyone but himself and his Corps, although recently, many of them had lost faith in him as well.

3. He actually considers Hal Jordan a friend after all they've been through

Although Hal Jordan has been the biggest thorn in Sinestro’s side, he's also the one with the experience to best understand the villain. Sinestro was his mentor and the two were close friends before Jordan was forced, by Sinestro’s actions, to turn against him. Over the years, he and Hal have clashed time and time again, with Sinestro always intent on exterminating his arch-nemesis.

Despite this history of violence, in Green Lantern vol 5 #20, Sinestro confessed to Hal that he feels that they will always be friends. While this was a somewhat surprising statement, it does add up. The two men have been to hell and back together, and when things were at their bleakest, they had no choice but to reach out to one another. They have proven more than once that they are capable of accomplishing incredible acts together. Also, let’s face it, Sinestro doesn’t really have any friends. He’s fairly emotionally stunted, and cares only about his daughter. It makes a strange kind of sense that Sinestro would see Hal as a confidant.

2. Despite Green Lantern's box office performance, Mark Strong really enjoyed playing Sinestro

Although Green Lantern was both a critical and commercial flop, Mark Strong’s portrayal of Sinestro was considered to be the film’s one shining moment of success. His performance perfectly captured a Sinestro who had yet to become corrupted (although a mid-credits scene sets the stage), and served as Hal Jordan’s mentor in the film. Fans and critics alike have speculated that he would’ve done an awesome job playing Sinestro as a fully realized villain in the sequel that never happened.

Strong has stated in interviews that it's unlikely he'd reprise the role, due to the fact that the reboot would have a whole new cast. Although he maintains that fact, the actor has also stated that he would love to play Sinestro again. Despite all the hate from fans, he stands behind the film completely. For him, the entire experience of making the movie was a great one, and that shines through in his effortless performance.

1. Mark Strong fought against Sinestro having a ponytail in the film

Growing up in England, Mark Strong was largely unfamiliar with both Marvel and DC Comics, so in an effort to prepare for his role as Sinestro, he dove right in. He found much to love in the pages of Green Lantern. In fact, he loved it so much, that Sinestro’s appearance became incredibly significant to him. He wanted to be certain the character was faithfully rendered in the film.

Strong had done his research! He knew both the character’s origins and his motivations, and apparently the earliest concepts for Sinestro were drastically different, most notably, the way he looked. The character was sporting a goatee and a ponytail. While Sinestro did have a similar appearance at one point in the comics, it is certainly not his most iconic look and therefore, not what fans would be expecting. Strong was insistent that the character’s look match the source material. Like fans, he felt that if you’re not going to do something right, it’s not worth doing. Too bad the rest of the film didn’t resonate the way that his performance as Sinestro did.