November 9, 1885–December 9, 1955

BY MICHAEL ATIYAH

HERMANN WEYL WAS one of the greatest mathematicians of the first half of the twentieth century. He made fundamental contributions to most branches of mathematics, and he also took a serious interest in theoretical physics.

It is somewhat unusual to write a biographical memoir nearly 50 years after the death of the subject, and this presents me with both difficulties and opportunities. The difficulties are obvious: I had essentially no personal contact with Weyl, hearing him lecture only once at the international congress in Amsterdam in 1954, when I was a research student. His contemporaries are long since gone and only a few personal reminiscences survive. On the other hand the passage of time makes it easier to assess the long-term significance of Weyl’s work, to see how his ideas have influenced his successors and helped to shape mathematics and physics in the second half of the twentieth century. In fact, the last 50 years have seen a remarkable blossoming of just those areas that Weyl initiated. In retrospect one might almost say that he defined the agenda and provided the proper framework for what followed.

I shall therefore take the liberty of connecting Weyl’s own work with subsequent developments. This means that I