In May 2009 the Leuven Institute of Early Christian and Byzantine Studies organized an international congress, with the title: Encyclopedic Trends in Byzantium? Some 40 scholars discussed the concept of Byzantine "encyclopedism", a notion coined definitively in 1971 by the French scholar Paul Lemerle as a characterization of Byzantine culture for the period 800-1000: the emphasis was not on creativity, but on collecting and copying; until very recent times the term "encyclopedism" has been repeated rather rashly in all kind of publications. Many problems have been dealt with during our congress: e.g. what are the definition and characteristics of Byzantine "encyclopedism"? Does the Byzantine understanding of this notion differ from ours? Has this really been the main feature of the period studied by Lemerle? Do these compilations mirror the broader cultural atmosphere in Byzantium? Which are the strategies (theological, literary, political) playing a part in the Byzantine art of compiling? The proceedings, containing more than 20 articles, pave the way for a prudent assessment of the so-called Byzantine "encyclopedism".