http://grbs.library.duke.edu/article/viewFile/9961/4455 Byzantine Attitudes toward Islam during the Late Middle Ages by Speros Vryonis Jr
...In ancient times they crossed the Danube, plundered Thrace, and passing through the Ionian regions they overran Italy, the Celtic lands, Spain, and crossed over into Libya. In more recent times these 'Scythians' have enslaved most of Asia, Babylon, Assyria and lands as far as India.
...The term 'Scythian', as Metochites employs it, refers to all the Germanic peoples of the early mediaeval period as well as to the Turks and Mongols.
...The parallel between Metochites and Tacitus is striking: both moralize and use the 'noble savage' as a literary device to this end.