Star Wars: Episode III – Revenge of the Sith was premiered in the US on May 16th, 2005.
At the climax of the film, Obi-Wan and Anakin (played by Hayden Christensen) are facing off in a duel on the lava planet Mustafar, when at some point Kenobi jumps on the top of a hill, then telling Anakin “I have the high ground”.
The quote became popular among fans, spawning parodies and jokes online.
Early examples of “I have the high ground” appearing in jokes are a Lego comic as well as a Demotivational Poster, referring to the stand-off.
The quote would be frequently used on 4chan as far back as 2013 and it would appear on Reddit threads in 2017.
Robot Chicken also parodied the scene, with the clip having been uploaded to the YouTube channel of Adult Swim on March 21st, 2016.