Who were these Great Huns??

The Huns were barbaric people who descended from the Asian steppes around 200 AD. They came and settled near the Danube. They were barbaric people..ruthless and cunning. They had no fear of god.They just raided and slaughtered.They had no palaces..no villas..in fact compared to their rival, the Eastern and the Western Roman Empires they were just a small nomadic tribe..up to no good.They were in fact..many small tribal groups..ruled by chieftains until Rugila, a great king, united them all in 432 AD.The question arises here that why did the huns find only Europe as a settling place and not the whole of Asia? I request visitors to express thier opinions on this question..with their reasons of course..i am in the dark over this..i hope your opinions will show me some light.