With its emotionally devastating, cliffhanger ending, Avengers: Infinity War left Marvel Cinematic Universe fans clamoring for any detail they could get about next year's sequel, from official comments by the film's cast and crew to the actual, final title of the film itself. One of the longest-running and most refuted rumors regarding the fourth Avengers film concerns the expected premiere date of the sequel's first trailer.

The alleged debut of a trailer for the Infinity War sequel has been foretold seemingly more times than the apocalypse, with still no official footage from the film released online. It's got to the point where directors Joe and Anthony Russo refuse to discuss the trailer and its anticipated release date. Having just passed another rumored date for a trailer to drop, here's a history of the times an Avengers 4 trailer was expected to premiere, testing fans' patience again and again, just to be left waiting with little to show for it.

The first rumor regarding official footage being released from the upcoming sequel surfaced as early as last June, and was said to be part of Disney' presentation at CineEurope. The prospect of a full trailer debuting while Infinity War was still in theaters was unlikely, but fans hoped for a first official glimpse at the film, including the potential reveal of the sequel's title. To fans' disappointment, neither the final title or a teaser for the film debuted at the event.

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While the sequel was in the final round of reshoots last month, a new rumor allegedly describing a rough cut of the trailer was posted on Reddit before mysteriously being taken down. The Redditor claimed that the final title would be the long-rumored Avengers: Annihilation, and that the trailer release was imminent. While the removal of the post certainly helped fuel the rumors, a trailer failed to materialize, leaving many to wonder just how accurate the assumed trailer breakdown had been.

NEXT PAGE: The Avengers 4 Trailer is Confirmed to Release by the End of the Year (Probably)

Following Marvel Studios President Kevin Feige confirming that the first trailer for the Avengers sequel would premiere before the end of the year, a new rumor began making the rounds regarding when exactly the trailer would actually debut. A Russian social media site claimed that they had learned Marvel Studios had licensed the use of Twelve Titans Music's track "Dust and Light" for use during the trailer for an expected release by the end of November, with the official title of the Infinity War follow-up also allegedly being Avengers: Annihilation. With only one day left in November at the time of writing, there is still time for this rumor to be proven true, though it is highly unlikely at this point.

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The latest round of Avengers 4 trailer rumors surfaced following the Thanksgiving holiday weekend, after the premiere of the first trailer for the Lion King CGI remake. Still maintaining that a November debut was imminent, the reports indicated that, to echo Infinity War's marketing strategy, a trailer would debut on the final Wednesday of November. These rumors were further fueled by the entertainment site Collider hosting a special screening of Infinity War the same day, with the Russo Brothers confirmed to participate in an audience Q&A following the screening, as well as a prequel comic launching the following week on Dec. 5.

With the final Wednesday in November having now come and gone, along with the Russos' Q&A, and nary a sign of the Avengers trailer nor an announced release date for it, the latest rumor, of course, has been proven false, leaving MCU fans ravenous for any official details about the film. With a little over a month left in 2018, the clock is ticking on Feige's previous claim that a trailer will premiere before the end of the year.

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As the first superhero film to earn over $2 billion at the worldwide box office, it is not a stretch to say that the fourth Avengers film is one of the most eagerly anticipated sequels of all time. Following the cliffhanger at the end of Infinity War, it is perfectly understandable that Marvel Studios would employ a more deliberate and quiet marketing strategy for the followup. However, fan expectation and anticipation for an official first look at the film are already through the roof. With Mary Poppins Returns currently scheduled as Disney's last major release of 2018, perhaps the long-awaited trailer will finally be released before the film's premiere on Dec. 19. Mark your calendars... again.

The untitled sequel to Avengers: Infinity War will release on May 3, 2019. Directed by Joe and Anthony Russo, it stars Robert Downey Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Sebastian Stan, Benedict Cumberbatch, Paul Bettany, Samuel L. Jackson, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Pom Klementieff, Scarlett Johansson, Tom Holland and Anthony Mackie.