During this week's edition of The Star Wars Show web series, Lucasfilm revealed the first look and details of the droid C2-B5. He (or, rather, it) is essentially a black-painted R2-D2 because, as we learn in the video shown below, both are part of the astromech droid family.
First introduced in 2015's Darth Vader #3 by Kieron Gillen and Salvador Larroca, BT-1 ("BeeTee" for short) is a one-droid army that revels in death and destruction. BT-1 is presented as an evil equivalent to the beloved astromech R2-D2, and of course he has his own C-3PO in the vicious assassin droid 0-0-0.
To keep audiences thinking that R2-D2 was moving all by himself, Kenny Baker's legs were hidden using pipes that led to the droid's feet. This allowed him to control the astromech's movement when he was hidden inside.
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.
R4-K5 was an astromech droid that accompanied Sith Lord Darth Vader, formerly Jedi Knight Anakin Skywalker, on missions for the Galactic Empire early during the Imperial Period. Once owned by a Jedi, R4-K5 was chosen for its dark hue by Vader to replace his former astromech droid, R2-D2.
Real-world: they weren't connected when the original films were written. Same goes for how he didn't sense Leia's relation to him or Force abilities when standing directly in front of her.
Yoda soon agrees to train Luke about the Force and how to be a Jedi. We believe this is the first meeting between all three. But in the “Star Wars” prequel trilogy, we learn R2D2 and Yoda ran in some of the same social circle. And now, a new book has confirmed that Yoda knew who R2D2 was in “Empire Strikes Back.”
As such, by the time of Anakin and Padme's marriage, Anakin was the owner of C3PO and Padme the owner of R2D2 (or the state of Naboo).
With the release of Star Wars Clone Wars Season 7 Episode 11 Shattered we finally know that Rex knew about Vader when he mentioned it to Ahsoka as she found out from Maul.
R2-D2 was designed in artwork by Ralph McQuarrie, co-developed by John Stears and built by Peteric Engineering. The revised Empire Strikes Back droids had fibreglass shells built by Tony Dyson and his White Horse Toy Company.
Clearly the technology was there to let him speak, but whoever designed him intentionally decided to stick with the beeps and whistles.
He'll always be remembered by so many fans. Did the two men hate each other? Maybe 'hate' is too strong of a word. According to Baker, they just didn't like each other's company, and one may have been more at fault than the other.
As mentioned earlier, R5 was the red astromech droid that Luke's Uncle Owen was about to purchase before it malfunctioned, leading Owen and Luke to purchase R2-D2. R5 also appeared in earlier episodes of both The Mandalorian and The Book of Boba Fett as a cameo.
Binary. Binary, or Droidspeak, is made up of beeps and whistles. The language is “spoken” by droids such as R2-D2 and BB-8.
Towards the end of the war, Anakin turned to the dark side and Padme died so her friend, Bail Organa took the droid as well as R2 when he took her daughter, Leia. C-3PO has his memory wiped unlike R2-D2.
After C-3PO and R2-D2 landed on Tatooine, Jawas picked up the two droids, fitting them with restraining bolts. The Jawas sold the robots to Owen and Beru Lars and their nephew Luke Skywalker, a seemingly minor event that would change the fate of trillions in the galaxy.
Anakin was still very young, so he grew up and became a Jedi with R2 at his side. Star Wars: The Clone Wars detailed their friendship at length, devoting entire arcs to it. They were inseparable, even as Anakin's faith in the Jedi Order and the Republic started to falter.
After the battle, R2-D2 and C-3PO were the sole witnesses to the marriage of Anakin Skywalker and Padmé Amidala in Lake Country. After this Padmé gave ownership of R2 to Anakin while she kept 3PO.
R2-D2, the indomitable droid and mainstay of the Star Wars series, may be responsible for one more incredible feat: saving Grogu.
Darth Vader didn't learn he had a daughter until Return of the Jedi, when he stood before Emperor Palpatine. The Emperor's power probed Luke's mind, attempting to goad him to fall to the dark side, and he discovered Leia's existence. "Sister," the Emperor taunted.
You'll remember that, in the conclusion of Revenge of the Sith, C-3PO's memory is wiped, so he loses his knowledge of the past. R2's isn't stated to be erased, so he presumably maintains his memories; why does he never tell Luke about Anakin? Well, maybe he didn't want to.
Theory 1: Leia Doesn't Remember Ben Is Obi-Wan
Throughout her encounters with Kenobi in the series, he refers to himself as Ben. The most straightforward explanation would be that Leia knows the person who rescued her is Ben, and never connected the dots that Ben is actually Obi-Wan.
The base assumption of why Obi-Wan doesn't remember R2-D2 -- in light of the prequels -- is that Obi-Wan is feigning ignorance in A New Hope to downplay the importance of the droid's arrival.
In Death Star, it seems the Sith Lord could have discovered Leia's true identity if he'd pursued his hunch. However, Leia's strong-mindedness during Vader's probe denied him the opportunity to discover she was his daughter.