Born in Saxony as Peter Bienewitz, Petrus Apianus was a prolific publisher of mathematical and astronomical texts. Apianus was educated at Leipzig University. His most distinguished patron was 

 Charles V, who commissioned Apianus’ greatest work, the

. This book included twenty-one volvelles, which could theoretically be used to calculate everything from eclipses to the time of a baby’s conception. The 

 made Apianus famous, earning him the positions of Imperial Knight and Imperial Court Palatine in Charles V’s court. Apianus was known for making cosmography accessible to his readers, which can be seen in his earlier text, the 

 (1524). It used interactive paper instruments to explain sixteenth century innovations and ancient knowledge.

Black and white portrait of Petrus Apianus