Assoc. Prof. Marek Dulinicz, a researcher at the Institute of Archaeology and Ethnology of the Polish Academy of Sciences, deputy director of the Institute for scientific affairs, lecturer at the Cardinal Stefan Wyszynski University in Warsaw and the Aleksander Gieysztor Pultusk Academy of Humanities, specialist on Early Medieval European archaeology and especially the archaeology of Western Slavs, died together with his wife in a car accident on 6 June 2010. He had been part of our Institute for thirty years, having joined the staff right after receiving his diploma from the University of Warsaw on the grounds of an MA study on Settlement in the late period of Roman influences and Early Middle Ages in southeastern Poland. He was first associated with the Institute as a PhD candidate, and in 1988 he obtained his doctoral degree for the dissertation in the field of archaeology on Settlement processes in Masovia (from the younger Pre-Roman period until the Early Middle Ages). In 2002 he received a habilitation degree in archaeology (his book was devoted to The emergence of northwestern Slavdom. Archaeological study). In 1994-2002, Marek Dulinicz headed the Institute's Department of the Archaeology of Masovia and Podlaquia; in 2003, he was nominated deputy director of the Institute for scientific affairs. Both his field and office research were impressive to say the least. The research interests were concentrated around key issues of the Middle Ages in mainly Masovia and Podlaquia and central Europe. He was a member or head of research teams and author of comprehensive reports on excavations conducted on several dozen archaeological sites, mainly in Masovia; he directed the work of the Masovian Archaeological Expedition, he coordinated the Masovian part of the Research Program Poland in the Days of the Gniezno Assembly, and research connected with rescuing the cultural heritage of eastern Masovia. Some of these projects were carried out in association with abroad institutions. One should mention a joint project (1994-1999) with the Johann Wolfgang Goethe Universität in Frankfurt am Main, aimed at archaeological verification of Early Medieval strongholds in Masovia; finally, the program Archaeological research on early Slavic settlement in the Middle Vistula basin, co-financed by the Polish-German Cooperation Foundation, the Alexander von Humboldt Foundation and the Institute, which M. Dulinicz directed together with Dr. Felix Biermann. Other research projects included in 1998-2008 the Slavs as an element of the Medieval european cultural mosaic, engendering numerous publications, including books. He was also actively involved in preparing comprehensive reforms that were to adapt the Institute to the new conditions set before Polish science.He as part of the international scholarly circuit from the very beginning during his sholarship grants from the Alexander von Humboldt Foundation and the Conference of Rectors of Science Academies in Germany's Federation Lands; frequently visiting European countries. He was an active member of various organizations and scientific editorial boards. Marek Dulinicz was a prudent and industrious man, searching for optimal solutions to difficult problems, a perfect administrator, but foremost a researcher of European standing.