Johann Heiss is Wissenschaftlicher Mitarbeiter at the Institute for Social Anthropology of the Austrian Academy of Science, and member of the VISCOM Project Part dealing with "South Arabia between Late Antiquity and and Early Modernity", where he focuses on religious and political developments in Yemen between the 10th and the 14th centuries as well as on the early views on tribal organization in southern Arabia in Byzantine and early Arabic literature. He finished his PhD Thesis on "Tribale Selbstorganisation und Konfliktregelung. Der Norden des Jemen zur Zeit des ersten Imams (10. Jh.)" in 1998, and has since then participated, amongst others, in the Wittgenstein Project "Lokale Identitäten und Überlokale Einflüsse" under prof. Andre Gingrich. Apart from his work for VISCOM, Johan Heiss currently studies the visible impact of the Ottoman Conquest of Central Europe, and is also interested in the development of social networks, the perception of "The Other" through the ages, and cultural contacts between Europe and the near East in the High Middle Ages.