Norbert Schappacher is a German mathematician and historian of mathematics. He was an Invited Speaker at the International Congress of Mathematicians in 2010 in Hyderabad.

Diophantus of Alexandria was a Greek mathematician, who was the author of two main works: On Polygonal Numbers, which survives incomplete, and the Arithmetica in thirteen books, most of it extant, made up of arithmetical problems that are solved through algebraic equations.