I'm pretty sure that calling the story of Anakin Skywalker a tragedy is nothing new. In fact, I'd say it's kind of the whole point. However, I think something that's often overlooked about his story is the fact that his story mirrors the classic tragedies of history. The earliest Greek plays were tragedies, many of Shakespeare's works were tragedies- for some reason, we've always loved a good, sad story.
To celebrate today's holiday of Revenge of the Sixth, I'll be going through the stages of a tragedy and how Anakin's story fits into them as a tragic character. While not all sources sort the stages of a tragedy neatly, I'll be using the stages as follows: Anticipation, Dream, Frustration, Nightmare, and Destruction. I'll also mostly be focusing on his story in the prequels (Revenge of the Sith specifically) out of acknowledgement for the holiday, and also because if I included all bits of Anakin/Vader content... we'd be here a while.
Also, I'd like to express that like similar structures that divide stories into stages such as this (like the Hero's Journey, for example), the stages can be slightly fluid and overlapping. Stories are not as clean cut as these academic walkthroughs could lead you to believe, and that's a good thing. I'll get more into it later.
Alright so first, the Anticipation stage. This is the earliest stage of a tragedy, where the protagonist begins to essentially want something that they feel is missing from their life. What does Anakin want? Well, a lot of things. He wants freedom, for the people he cares about to be safe, especially after his mother's death, and peace and justice across the galaxy. I think Anakin's Anticipation stage really starts in Attack of the Clones. Sure, you could argue that him wanting freedom as a boy in The Phantom Menace is part of that too, but I don't think that desire is really a part of his tragic narrative- he achieves freedom, and it isn't that freedom that leads him down his dark path. No, in Attack of the Clones, Anakin expresses many of his desires, the ones that directly tie into his descent to Darth Vader in the next film. Anakin wants to be with Padmé and he talks about wanting order across the galaxy that eliminates what he sees as petty squabbles by politicians. He seems to want to be treated with respect by his master and the rest of the Jedi, something he doesn't feel that he gets. These are the things that he wants, and the things that eventually lead to his downfall. But first... he has to enter the Dream stage.
The Dream stage, to put it mildly, is the happiest time in a tragic character's life. Things go very well for them, and they seem to have those things that they desired in the Anticipation stage. For Anakin, this Dream stage starts at the end of Attack of the Clones, runs through The Clone Wars and bleeds into the beginning of Revenge of the Sith. While of course bad things happen to him in that time, overall... Anakin has many of the things that he wants, or at least believes he's close to achieving them. He's married to Padmé, Rex, Obi-Wan and Ahsoka are alive and well and close to him more often than not, and he's fighting a war that he believes will lead the galaxy to peace. He gets to bring justice to people thinks have done wrong.
However, in The Clone Wars we begin to see this Dream stage overlapping with the Frustration stage. The Frustration stage, essentially, is when roadblocks start popping up for the protagonist, and they become frustrated, and deal with them in dark ways that signal their impending downfall. Anakin's Frustration phrase comes in rather slowly, which is why I say it overlaps with the Dream phase. In The Clone Wars, while Anakin may generally seem happy with the connections he's built in his life, sometimes he'll be pushed a little too far and commit an act that gives other characters and us viewers pause, usually accompanied by a little riff of Imperial March. I think the very best example in The Clone Wars is the rage that Anakin goes on after he thinks he loses Obi-Wan when he is "killed" by Rako Hardeen and goes undercover, when he brutally attacks Obi-Wan in disguise as Rako in an attempt for revenge. We see signs of it before The Clone Wars too, when he slaughters the Tusken Raiders after they kidnapped and killed Shmi. It also applies to his killing of Count Dooku in Revenge of the Sith, and I'd say his frustration stage continues all the way up to his murder of Mace Windu (or rather, assisting Palpatine in murdering him). That's when he reaches his true point of no return, and the Nightmare begins.
The Nightmare stage is not just when Anakin has his nightmares about Padmé dying. Though it would be pretty easy if it was. No, the Nightmare stage is when things really unravel and fall apart for the tragic character, where they become paranoid and fearful. It's pretty easy to see how things fall apart for Anakin. He's in a fragile state, being manipulated by Palpatine who promises him that the things he desires will come in due time, only if he does as instructed- slaughter the Jedi. The galaxy as Anakin knows it falls apart, and he's responsible. The paranoia that Anakin has in the latter part of Revenge of the Sith is also extremely present, especially when we reach Mustafar. We see Anakin being convinced that everyone is out to get him, especially when Obi-Wan steps off the ship. He suddenly believes that Padmé has betrayed him, despite her pleading that she didn't. His paranoia-fueled anger leads to his fight with Obi-Wan... and his Destruction.
The Destruction phase is probably the easiest to define. It is the destruction of the protagonist. Usually their death, like in many classic tragedies, but not with Anakin (well, not yet anyway). His Destruction at the hands of Obi-Wan is the last step that Anakin needs to fully die and become Darth Vader, clad in the mechanical suit. He is mourned by characters like Obi-Wan: not because he died, but because before he died he was no longer the person they all once loved and trusted. Anakin is destroyed with little fanfare, he does not get the funeral pyre like Qui-Gon does- not until decades later, when his actual death is greeted by mourning only from his son, and celebration from nearly every other being in the galaxy.
Anakin's tragic narrative differs some from many of the classic tragedies of old. But generally, I'd say it fits in with them very well. Anakin's story, in my opinion, is just a Shakespearian story set in space, which is why the Shakespeare's Star Wars books work so well. He is an unbelievably tragic figure, both because of his own decisions and the pressures that he cracks under. It makes him such an interesting, fleshed out character, and I'll always love his story for that.