If you thought you knew your Transformers history, you might want to watch a new trailer a few times and then enroll in remedial Optimus Prime 101.

The nearly three-minute trailer for "Transformers: The Last Knight" was released Wednesday. It blends legends and history with the franchise's giant creatures. Um, did you know the Transformers stood beside medieval knights at King Arthur's round table? (Hence the movie's subtitle.) Jon Snow from "Game of Thrones " could use a few of them at the Wall.

But if an alternative past is not your style, hang in there. The trailer is also jam-packed with robot-fighting action, including a massive Optimus Prime-Bumblebee battle. And remember, filmmaker Michael Bay said there are 14 more Transformers stories coming.

"Transformers: The Last Knight" opens June 23 in the US and UK and June 22 in Australia.