  The first direct experimental test of Einstein's theory of general relativity
involved a pair of expeditions to measure the bending of light at a total solar
eclipse that took place one hundred years ago, on 29 May 1919. So famous is
this experiment, and so dramatic was the impact on Einstein himself, that
history tends not to recognise the controversy that surrounded the results at
the time. In this article, I discuss the experiment in its scientific and
historical background context and explain why it was, and is, such an important
episode in the development of modern physics.
