As he entered his seventies, the great Italian Renaissance artist Michelangelo despaired that his productive years were past. Anguished by the death of friends and discouraged by the loss of commissions to younger artists, this supreme painter and sculptor began carving his own tomb. It was at this unlikely moment that fate intervened to task Michelangelo with the most ambitious and daunting project of his long creative life. 'Michelangelo, God's...