Peter Stevenhagen is a number theorist who obtained his PhD at the University of California at Berkeley and started his career in the CNRS in France. Since then, he has been employed at the University of Amsterdam and, as of 2000, at Leiden University, where was for many years the scientific director of the Mathematical Institute. His publications focus on algebraic, algorithmic and historical aspects of number theory. 
He has traveled widely, giving invited conference and seminar talks and participating in research schools in Europe, Asia, Australia, North and South America.
Stevenhagen is one of the founding fathers and the current chairman of the European Master program ALGANT in Algebra, Geometry and Number Theory, which graduated hundreds of master students and more than 40 PhD students since its creation in 2004. The consortium now involves Dutch, French, Italian, German, Canadian and South African partners.