During the Year of the Four Emperors (69 CE), the fight between Vitellius and Vespasian would ultimately bring about the demise of four legions, the XV Primigenia, I Germanica, IIII Macedonica, and XVI Gallia. All four of these legions had previously served the Roman Empire with distinction under such leaders as Pompey and Octavian but made what turned out to be the wrong choice in 69 CE. While there remains a question concerning the loyalty of XV Primigenia, three of the legions made the mistake of supporting Vitellius.
This is a companion discussion topic for the original content at https://www.worldhistory.org/article/1724/the-year-of-the-four-emperors--the-demise-of-four/.