Who was Alfred North Whitehead?

Alfred North Whitehead was an English mathematician and philosopher. He is most remembered for his book Principia Mathematica which he coauthored with his former student Bertrand Russell.

Principia Mathematica played a major role in the events leading up to the Turing Machine.

After the publication of the last volume of this book, Whitehead's attention drifted away from mathematics and he devoted most of his time to philosophy and metaphysics.