In that mountain province called Farsistan, north-east of what we now call Persia, the dwelling-place of the Persians, there dwelt, in the sixth and seventh centuries before Christ, a hardy tribe, of the purest blood of Iran, a branch of the same race as the Celtic, Teutonic, Greek, and Hindoo, and speaking a tongue akin to theirs. They had wandered thither, say their legends, out of the far north-east, from off some lofty plateau of Central Asia, driven out by the increasing cold, which left them but two mouths of summer to ten of winter.