A conversation with Richard Calis (Utrecht University) about Martin Crusius (aka Kraus: 1526-1607 AD), one of the first philologist-historians who tried to reconstruct Byzantine history from the sources. We talk about his interest in the Greek language and the Ottoman empire, in using Byzantine sources to understand antiquity, and his working methods -- all in an era before there was much scholarship to guide him. The conversation is based on Richard's chapter 'Martin Crusius's Lost Byzantine Legacy,' in N. Aschenbrenner and J. Ransohoff, eds., The Invention of Byzantium in Early Modern Europe (Washington, D.C.: Dumbarton Oaks, 2021) 105-142.