Ibn Khordadbeh
Ibn Khordadbeh observed and recorded routes of Jewish merchants in his Book of Roads and Kingdoms from the South of France to Spain, carrying (amongst other things) female slaves, eunuch slaves, and young slave boys. He also notes Jews purchasing Slavic slaves in Prague. Letters of Agobard, archbishop of Lyons (816–840), acts of the emperor Louis the Pious, and the seventy-fifth canon of the Council of Meaux of 845 confirms the existence of a route used by Jewish traders with Slavic slaves through the Alps to Lyon, to Southern France, to Spain.