In the main Star Wars canon, Darth Vader and Darth Maul never met, let alone fought. When Obi-Wan Kenobi defeated Darth Maul in Star Wars: Episode 1 - The Phantom Menace, Anakin was still a kid and just joined the recently crowned Jedi Knight as his apprentice.
That includes the Siege of Mandalore, in which Anakin would have participated had it not been for the Chancellor's kidnapping. But their story began years before that, Darth Maul and Anakin's paths briefly crossed in Tatooine and later in Naboo.
Star Wars: The Clone Wars season 7 strongly suggests Darth Maul had figured out Anakin Skywalker's fate. He had deduced Darth Sidious' plans, figuring out the Emperor's goal was to seduce Anakin Skywalker to the dark side, and consequently, he would have immediately guessed who this mysterious Sith Lord really was.
Luke never meets Darth Maul in this life
Of course, the survival of Darth Maul isn't terribly shocking to those who watched the animated Star Wars series, which covers the narrative a bit. And not only does Maul survive, but he lives into the years that Luke Skywalker comes onto the scene.
Darth Maul feared Vader in the same way as anyone would. Vader was the most notorious and ruthless figure in the Empire, using his rage and anguish to fuel his resolve, enabling him to dispatch his enemies without compassion or remorse.
Thought dead, Darth Maul survived his injuries by focusing on his hatred of Obi-Wan Kenobi, the Jedi who cut him in half. His shattered body was dumped amid the refuse of the junk planet Lotho Minor, where the once deadly warrior fell into madness, staying alive on a diet of vermin.
During Palpatine's reign as Emperor, his apprentice's true identity was kept a secret, leaving only a few Star Wars characters aware Anakin was Darth Vader. Besides Obi-Wan, Master Yoda also knew the truth, as well as Ahsoka Tano, R2-D2 and C-3Po, and even Senator Bail Organa.
Yoda didn't specifically know how this would go down, or to what degree Anakin would cause it to happen, but he was playing a much longer game by Revenge of the Sith, and that's at least, in part, explained by Yoda's Force connection with Qui-Gon's spirit.
Fandom. Question: Did Maul know Sidious was Palpatine? In legends he did. In the darth plagueis novel I'm pretty sure there's a part where maul was reflecting on his master's political machinations and how he is publicly known as palpatine.
Darth Maul and Obi-Wan's long-standing rivalry started in Episode 1 and lasted all the way until Star Wars: Rebels. Throughout his lifetime, Maul seemed to hate Kenobi! Every time Maul says Kenobi.
He ignites his new double-bladed lightsaber and engages Obi-Wan in a duel, but Obi-Wan again bests him in combat, cutting off his opponent's horns. Maul is killed by a blaster bolt to the head from Owen Lars. Obi-Wan thanks Owen, and says he will take Maul's body into the desert and burn it.
By surviving his encounter with Obi Wan and living after being replaced by Dooku, Maul effectively breaks the rule of two and continues to do so throughout the clone wars and rebels series. The rule of two states there can only be two, a master and an apprentice. As Maul is neither, he cannot be Sith.
In fact, in this same scene, Sidious says he is keeping Maul alive because he has "other uses for you!" If Palpatine thought Maul knew he about his double identity, there's no way he would have let him stay alive.
And while his warnings don't work, at the very least, it shows that Maul became aware of Anakin and what he would soon become. With the rise of the Empire, it's likely Maul caught on to Vader's existence pretty quickly.
Padmé was well aware that Anakin had committed dark crimes that would've started his fall to the dark side. He even confessed to her that he had massacred an entire Tusken Raider village to avenge his mother, leaving no one alive.
R2-D2 was present when Padmé gave birth to Leia and Luke, so he knew Luke was Anakin's son – but what he didn't know was that Anakin became Darth Vader. In addition to that, Anakin's fall was surely a painful event in R2-D2's life, one that he definitely wouldn't like to remember or even talk about.
As Anakin's confusion and anxiety grew, Palpatine told him a Sith legend that spoke of the ability to stop people from dying. Entranced, Anakin was desperate to learn this power. Palpatine revealed himself to be a Sith Lord, Darth Sidious, and promised to train him in the ways of the dark side.
They pulled this kid out of slavery, away from his mother and everyone he knew, and dropped him in an unfamiliar setting on a completely different planet. He was a kid. The Jedi, with the exception of Obi Wan (and Qui Gon before he died), openly distrusted and even disliked Anakin.
In the material around the film from the Legends timeline, it's established that by the end of Star Wars: Episode III - Revenge of the Sith, Kenobi was one of the characters who knew Anakin's Sith name was Darth Vader. However, what he didn't know was that he was still alive after Mustafar.
Despite seeing Vader as an idol, Kylo conveniently ignored his grandfather's redemption. He was well aware of what happened, and it's likely Luke himself who told Ben about the events of Star Wars: Return of the Jedi.
Star Wars is finally exploring Leia's emotional reaction to the revelation Darth Vader was really her father - as her identity is transformed. Star Wars has finally revealed Princess Leia's reaction to learning Darth Vader was her father.
Darth Maul lives! Well, sort of. After Obi-Wan Kenobi famously cut the horned Sith Lord in half in The Phantom Menace, Maul resurfaced in The Clone Wars, became a crime lord by the time of Solo, and eventually was murdered by Obi-Wan (again!) in Rebels.
Moments later, Vader confronts him, and they engage in a lightsaber duel. Obi-Wan uses the duel to distract Vader as Luke, Leia, Han, and Chewbacca escape to the Falcon. Obi-Wan allows Vader to strike him down, and his body mysteriously vanishes the moment he dies.
But if you've not seen the movie yet and want to go in entirely fresh, now is the time to leave. So, let's just get the super obvious out of the way. Yes, that was the character formerly known as Darth Maul you saw in hologram form at the end of Solo: A Star Wars Story.