Transformers One tells the untold origin story of how Optimus Prime and Megatron went from BFFs to sworn enemies, and since it's set in the past, there have been some changes to who's playing them.

Transformers One has arrived in theaters, surprising new and old fans of this legendary franchise. This film is taking fans back to the beginning with new origins for some of your favorite Autobots ...

Watch all eight Transformers movies chronologically, from ancient Cybertron through Bumblebee’s early Earth adventures today.