20 Secrets of the Sistine Chapel

The Sistine Chapel was built from 1475 to 1481, using part of the walls of a previous construction, the Cappella Magna. Dedicated to the Assumption of Mary, it takes its present name from Pope Sixtus IV, who ordered its construction.
It’s the Pope's private chapel, and is considered one of the most complete and significant works of "visual theology," in the tradition of the "Biblia Pauperum" (the "Bible of the Poor”)—medieval picture books that illustrated important passages of the New Testament next to scenes that prefigured them in the Old Testament.
It has the same dimensions as the Temple of Solomon as described in the Old Testament.
Michelangelo’s paintings take up 11,840 square feet.
Since 1870, it has been the venue for the conclave, the meeting in which the cardinal electors of the College of Cardinals elect a new pope. Once the pope has been elected, he is taken to a small room in the Sistine Chapel known as the "Room of Tears." This room is located to the left of the altar under the Last Judgment, and has this name because new Popes often break into tears due to their intense emotions upon being elected.
The Sistine Chapel remains in use today, and continues to be the venue for important events in the Papal calendar. For example, every year a Mass is celebrated there on the occasion of the Feast of the Baptism of the Lord, during which the Holy Father baptizes a number of babies.
The Papal Sistine Chapel Choir is the oldest active choir in the world. Among the pieces written specifically for this choir, the most famous is the Miserere by Gregorio Allegri.
The Sistine Chapel's fame is principally due to its frescoes, especially those which are the work of Michelangelo: the vaulted ceiling and the Final Judgment on the wall behind the altar. The artist accepted the commission somewhat against his will, because he considered himself more of a sculptor than a painter, but was not in a position to argue with the Pope, who was adamant that Michelangelo take the commission.
Michelangelo isn't the only famous artist who worked on the Sistine Chapel. Sixtus IV entrusted the frescoes on the walls to other famous painters, such as Sandro Boticelli, Domenico Ghirlandaio, and Pietro Perugino; Michelangelo was hired later by Pope Julius II for the ceiling (which originally had been painted with stars on a blue background) and by Clement VII for the Last Judgment.
Until the early Renaissance, God the Father was usually portrayed as a hand sticking out of the clouds. In the Sistine Chapel, Michelangelo depicted God the Father with a muscular body and a long white beard, which was a relatively recent development in Christian art, and echoes images of the Greek god Jupiter.
In order to paint the ceiling, Michelangelo built his own scaffolding, a wooden platform supported by brackets inserted into holes in the walls, at the height of the windows. Contrary to popular belief, he didn't lie down on the platform to paint; rather, he painted standing up—an awkward position which caused him great discomfort. He even wrote a poem about how uncomfortable he was while painting, and included a sketch of himself painting while standing up with his back arched backwards.
In 1990, physician Frank Meshberger published a paper in the Journal of the American Medical Association stating that the angels, robes, and shadows surrounding God in Michelangelo's Creation of Adam are an accurate depiction of the human brain in cross-section. Meshberger theorizes that this was Michelangelo's way of symbolizing God's bestowing intelligence on the newly-created Man.
From the construction of the Sistine Chapel until 1536, the wall behind the altar, where the Last Judgment is found today, was decorated with other murals from the series depicting stories from the lives of Moses and Jesus. They included Perugino's paintings of the Assumption, the Birth of Christ, and the Finding of Moses, which Michelangelo unfortunately had to sacrifice, which earned him abundant criticism.
The Last Judgment is painted in such a way that the top tilts slightly over the viewer , and was designed this way so that the fresco would inspire fear and respect for God's power. Unlike the frescoes by other painters in the chapel, the figures are very muscular and in twisted positions, including the Virgin Mary, who is at the center near Christ.
The composition is circular, moving clockwise starting at the bottom left: those who are to be judged rise on the left; the just ones remain above, while the condemned descend on the right, towards hell.
The central and most important figure is Christ the Judge, a young, athletic, and muscular figure. His gaze is stern, facing his left, towards Hell and its sufferings. The time of mercy has passed; here we see Christ enacting justice, separating the “sheep from the goats” and casting those who are unworthy into eternal fire.
To the right under Christ's feet is Saint Bartholomew. In one hand, he holds the knife with which he was flayed alive; in the other, he holds his skin (all in one piece) after it was stripped off his body. The face on the dangling skin is a self-portrait of Michelangelo. One of the interpretations of this is that it might reflect Michelangelo’s tortured spirit—at the time he was painting this image, he was elderly and experiencing a crisis of faith. There is also another interpretation: since he hadn’t wanted to accept the commission of painting the mural, he felt he’d rather be skinned alive than do that job.
The Last Judgment caused an argument between Cardinal Gian Pietro Carafa and Michelangelo. Because the painting includes nudes, the artist was accused of obscenity and immorality. Carafa and Nino Sernini (the ambassador of Mantua) organized the so-called "fig leaf campaign" to have the frescoes censored, and possibly totally erased.

The papal master of ceremonies, Biagio de Cesena, was particularly opposed to Michelangelo’s work. He felt it was shameful that such a holy place should house a representation of all those nude figures. He went so far as to say that the paintings were appropriate "for the public baths and taverns," but not for a papal chapel. Michelangelo reacted to the criticism by painting his detractor’s likeness in the fresco as Minos, the judge of hell, with donkey ears and a snake biting his genitals. It's said that when Cesena complained to the Pope, the pontiff replied by saying that his authority reached Purgatory, but not Hell, so the portrait would have to remain.
After Michelangelo's death, the proponents of censorship won a partial victory, and the genitals of the nudes were painted over by Daniele da Volterra, who thus won the nickname "the Braghettone" ("the breeches maker").