The Wachowski siblings' Matrix sequels, along with Quentin Tarantino and his Kill Bill series, ushered the concept of the two-parter into the mainstream in the 21st century. Multi-part movies before were few and far between (examples include Back to the Future Part II and Part III in the '90s, Richard Donner planned it with Superman: The Movie at the urging of his producers, who themselves had done the same thing with their early '70s adaptation of The Three Musketeers), but the two Matrix sequels got things into gear by filming the two-part sequel series as one massive production and releasing the pics, Reloaded and Revolutions, within six months of one another. Although the third installment would receive underwhelming attention at the theaters, the second chapter made bank.
Meanwhile, Kill Bill Vol. 1 and Kill Bill Vol. 2 came along after the filmmaker decided to turn what was meant to be a single film into two chapters based on the scale of material at hand. The decision to release the movie in two separate parts was announced in the post-production phase, when Tarantino showed then-Miramax head Harvey Weinstein half of the three-hour pic, and the two agreed it should be split. Rather than break the story up at the linear midpoint for a streamlined story, the timelines of the two parts are instead interwoven with flashbacks, each segment a piece of a larger puzzle which, together, create one character arc, thus making both films necessary for the full story. It was a lucrative decision indeed; with a total $60 million dollar budget, the films together earned more than $330 million worldwide.