Why is it canonical?

One of Michelangelo's greatest accomplishments, the ceiling of the Sistine Chapel (commissioned by Pope Julius II), shows his mastery as a painter (his mastery as a sculptor had been long established by then). With the Sistine Chapel ceiling, Michelangelo brought fresco painting, color, and anatomical naturalism to levels previously unseen in European art. Some of Western culture's most famous and resonant images appear on this ceiling, which solidified forever Michelangelo's incredible talent and skill.