Johannes Trithemius (1462-1516), German abbot and polymath. Born as Johann Heidenberg at Trittenheim, he studied at Heidelberg. During a journey home he was caught in a snow storm and took refuge in a monastery near Bad Kreuznach, where he stayed and was elected abbot at the age of 21. He dramatically increased the library, although he gained a reputation as a magician whch didn't sit well with the authorities. Eventually he moved to an abbey at Wurzburg. He is best known for his book Steganographia. Published 90 years after his death, this book appears to be about magic as it talks about using spirits to communicate over distance, but is actually a text on cryptography and steganography - the art of concealing messages in open text in a book. This engraving comes from his book Trithemius sui-ipsus vindex, published at Ingolstadt in 1616.