It’s from Warcraft 3. World of Warcraft sounds different though. I think W3’s soundtrack sound more like Celtic but with a twist, not just Celtic and WoW’s soundtrack sounds more orchestral but I think orchestral music fits beeter with futuristic scifi games like Tiberian Twilight and StarCraft 2.
I just like to listen to those kind of music when modelling a medieval style scene. They give inspiration.