Modern Control Engineering

Adolph Hurwitz was born on the 26th March in Hildesheim, a town then in the State of Hanover, now part of N.W. Germany. He studied mathematics, first at the University of Berlin and subsequently at Leipzig, where he was awarded the degree of Ph.D. , at the early age of 22. Twelve years later he was awarded a chair at Zurich Politechnic and remained in Zurich for the rest of his life.

As far as we are concerned his most important work was on polynomials having all their zeroes restricted to the left half of the complex plain. (Now known as Hurwitz Polynomials.) These have a key role in forming stable control functions.