Horsemen tried various remedies, and by the sixth and seventh centuries began nailing metal shoes onto their horses' feet. - See more at: http://www.equisearch.com/article/eqhorsesho610#sthash.qxxdJaMB.dpuf (http://www.equisearch.com/article/eqhorsesho610#sthash.qxxdJaMB.dpuf)
The Huns were a nomadic group of people who are known to have lived in Eastern Europe, the Caucasus, and Central Asia between the 1st century AD and the 7th century.
http://en.wikipedia.org/wiki/Huns (http://en.wikipedia.org/wiki/Huns)