Book hunters are the secret heroes of history. In times of greatest barbarism they tried to save what could be saved. Without the book hunters we would know far less about our own history. While libraries burned, church or secular rulers systematically destroyed unpopular literature, they collected and copied manuscripts. Only what the dedicated book hunters - mostly learned masters or cultured monks - got their hands on, what they tracked down or considered worthy, had a chance of being handed down. Thus the "Germania" of Tacitus reached the Middle Ages in only one single copy. Without Tacitus, we would know nothing of the unwritten Germania, would have no idea of the successful Battle of the Teutoburg Forest. And yet even the book hunters could not prevent an infinite amount of ancient knowledge being lost. Floor heating, window glass, aquaculture, aqueducts, architecture, medicine, mathematics.