Here is how The alliance between Berk and Equestria begins 3000 years ago in The Alliance of Berk and Equestria.
[The movie opens up with the Hasbro logo and then the Dreamworks Logo]
Yuna (narrating) Long ago, The Kingdom of Equestria and the Isle of Berk: homelands of Vikings and Equines lived together in peace and harmony. But everything changed when the Draconsequuses and the Great Lava Dragons attacked. Both the Viking and Equestria Equines both fought against the evil forces, but then one day, in order to end the war, Rukai, the great Equestrian Emperor (The First of the Alicorns) had to seal the passage to Isle of Berk and Equestria and then he vanished. 3000 years passed and my sister, cousins, and me rediscovered the Isle of Berk, and we meet up one of the Vikings: Hiccup Horrendous Haddock III. And his Dragon, a Night fury named, Toothless. And together, we shall bring the old Alliance back.
[the main series title then comes in "The Chronicles of Equestria and the Isle of Berk"]
[then in fades into the next title sequence "The Alliance of Berk and Equestria"]
(3000 Years Ago.)
(we see the Isle of Berk as the camera zooms in)
(We view the Vikings of Berk along with the Equines of Equestria)
Hamish I: This is truly a fine day.
King Flarebeam I: It certainly is. How goes the tribe?
Hamish I: It goes fine, how about the equines?
King Flarebeam I: Just fine, living in peace and harmony as normal.
[but then 3 days later]
Draconsequus Captain: Alright, my men! Let's get ready to wreak chaos!
Draconsequus soldiers: YEAH!!!!
Viking Scout: RUN!!
[but then a huge fireball hits one of the buildings of Berk]
(there in the sky, were Great Lava Dragons!)
Prince Flarebeam I: Great Lava Dragons!
[Great Lava Dragons shoot fire]
Equine Royal Guard: What do you want to do, Sire?
Prince Flarebeam I: Prepare our Soldiers for Battle!
Equine Royal Guard: YES, YOUR HIGHNESS!!
Hamish I: Attack!
[we now watch as the equines battle the Draconsequuses and the Vikings battle the Great Lava Dragons]
Prince Flarebeam I: Kill them! Kill them!
Hamish I: Do not let them escape! And make sure those dragons don't get the sheep!
[The dragons are trying to get the sheep but many of the Vikings prevent them from doing so]
Viking 1: Catapults!
[but as the days passed, it seemed like the Vikings and Equines wouldn't win]
Draconsequus: Sir, I believe if we continue this, we'll be able to do all the chaos' we want!
Draconsequus commander: Good!
Hamish I: Flarebeam! The Draconsequuses are too much for us!
Prince Flarebeam I: Keep going!
Hamish I: With Pleasure! RAH!!! [hits one of the Draconsequuses coming in]
[Both sides are straining against each other]
[then there was a bright light that came from the sky]
Prince Flarebeam I: Huh?
Hamish I: What in Odin's name is that?
[it revealed to be a regal alicorn that shined as bright as the sun]
Prince Flarebeam I: Rukai.
Rukai: [in thunderous voice] GREAT SPIRITS OF CHAOS'! YOU HAVE INVADED BERK AND EQUESTRIA LONG ENOUGH!! FOR YEARS WE'VE HAVE FOUGHT AGAINST YOU, BUT NOW THIS WAR COMES TO AN END NOW!!! [his horn lights up and then the draconsequuses ran]
[then the passage in between Equestria and Berk began to seal]
Hamish I: The passage is closing! All Vikings, back to Berk!
Prince Flarebeam I: Well, I guess this is it.
Hamish I: Yes, it looks like our time together is up.
Prince Flarebeam I: Farewell, My friend.
Hamish I: Same to you.
[they shake hoof and hand before Hamish I joins the fleeing Vikings and the passage closes up]
[but after the passageway closes, Rukai vanishes]
Prince Flarebeam I: Good bye, my old friend.