Alan Mathison Turing, born 1912, died 1954.
See the
Alan Turing Home Page
, presented by Andrew Hodges, author of 'Alan Turing: the Enigma'
Information on Turing Machines:
Andrew Hodges' "Computable Numbers, 1936, and the Turing Machine"
The
American Mathematical Society
has a page explaining
the Turing machine concept.