The medicine of medieval Europe was above all influenced by the Hippocratic and Galenic legacies, conveyed through the medical School of Salerno, albeit also more or less embedded in demonological, supernatural and folklore principles. But more concrete or extensive clinical descriptions of mental illness is hardly found beyond the anecdotic realm. However from the high middle ages (1100-1300, and Viking period 800-1030) the most vivid and universally available writings and descriptions in this respect stems from fictional literature, more precisely the sagas, written predominantly in Iceland, in the native language Old Icelandic during the 13th century. This was a period also called the “Old Norse Renaissance”, hallmarked by intense intellectual and literary activity and achievements. The literature of the period has given us a wealth of reports concerning everyday life and social life and mentality, with an eye for peculiarities and abnormalities.