A new teaser for "Transformers: The Last Knight" released today reveals that the Transformers have always been here to protect us, even from Nazis.

As Anthony Hopkins says in voiceover, as serious as any History Channel narrator: "It started as legend. One of the greatest of all. One of the oldest of all. But every legend has a secret. They have been here forever, in the shadows. To protect Earth from what was destined to arrive. A thousand years, we've kept it hidden... the secret history of Transformers."

We're treated to shots of the Transformers strolling through ancient buildings, crossing swords in a Musketeers-type salute and, of course, kicking Nazi ass. That's one history lesson we missed!

Watch the clip here:

"Transformers: The Last Knight" opens June 21.