Before and After...

So I wonder if all the events in Black and White the games happened before Ash got to the Unova Region.

Because Ash and friends went through the ruins of the legendary hero, Ash also went through the PokeStudios already and Virbank City.

So I'm wondering if BW and BW2 the game events happened before Ash got to the Unova Region.

Ehh it would be considered more of a parallel universe than it happening before one another but if it did it would deff be after since in the anime it seems like Cheren has been gym leader for a while

Anime and the Video games don't exist in the same space. They are two separate alternate universes. Which is why in the anime we have Younger Bianca and Older Cheren.

Xander's basically right. The anime universe and game universe are very separate, and some game characters don't even appear in the anime (an example being most in-game protagonists and Elite Four members) and this was why we had B/W Bianca and B2/W2 Cheren appear.

I think I agree with XanderO and Hikari10. Pokemon anime universe might be one of the parallel universe (which means game-based event might not apply in anime), because we still see the BW's Bianca and B2W2's Cheren here, and there is a separate story of Victini and Meloetta in anime.