• Leonardo Da Vinci’s “Last Supper” is one of the most famous – and consistently endangered – paintings in history.

• Don’t take Dan Brown’s popular novels too seriously – t he Renaissance artwork doesn’t really include secret codes or cryptic symbols.

• But Da Vinci’s piece does include a number of surprises, from the meals on the table to the gestures the Apostles are flashing.

Millions of people around the world are preparing to celebrate Easter.

Easter is the celebration of Jesus' resurrection, and one of the most famous images from that story is Leonardo da Vinci's "The Last Supper." It's an iconic Renaissance masterpiece that's been praised, studied, and copied for over 500 years.

Against all odds, the painting still lingers on the wall of the Convent of Santa Maria delle Grazie in Milan.

Da Vinci began the work in 1495 or 1496 and completed it around 1498. It depicts a famous scene from Holy Thursday, in which Jesus and his Apostles sharing a final meal before his death and resurrection. During the dinner, Jesus revealed that one of his disciples would betray him and hand him over to the authorities for execution (spoiler alert: It was Judas, who da Vinci depicts as spilling salt on the table, as part of some Renaissance pun).

Historian and author Ross King spoke with Business Insider about the mural. King said that his own lifelong fascination with da Vinci - who, as a painter, sculptor, inventor, and scientist, was really the ultimate Renaissance man - prompted him to write the book "Leonardo and the Last Supper."

"I was intrigued by him as a character - an artist, a scientist, a mountain climber, a rock collector, an all-around genius," he said.

Here's the story of "The Last Supper," which survived wars, prisoners, and its artist's identity crisis:

"The Last Supper" was hugely popular in its own time.

Foto: Giampietrino's copy of "The Last Supper" includes details from the original mural that have been lost. source Wikimedia Commons

While today da Vinci is remembered for the breadth of his artwork, writings, and inventions, "The Last Supper" was the painting that truly cemented his reputation during his own time. King said that the image immediately became famous all over Europe.

"It was the most copied painting of the next century - not only in paint, but also in marble, wax and terracotta," King said. "Everyone wanted a version of it. Leonardo had finally created the 'work of fame' about which he dreamed."

The painting's drama is heightened by its composition and details.

Foto: The "rule of thirds" applied to the mural. source Wikimedia Commons

The painting captures the Apostles' reaction to Jesus' famous declaration: "Truly, I say to you, one of you will betray me."

"Leonardo does justice to the episode like no one else," King said. "He grouped his 13 figures together on the same plane - a very difficult task - in such a way that each is individuated by gestures and expressions but none detracts from the overall effect."

Each figure is unique and memorable, down to the smallest details.

"Never before had an artist created such drama in a painting, with such lifelike figures and minute detail," he said. "Regarding detail, the right hand of Christ is a tour de force. Two joints of the little finger and the ball of his third fingers are seen through the transparency of a wine glass. It's an absolutely dazzling display of skill."

It's a miracle the painting has survived.

Foto: The mural still exists despite bombs, humidity, and centuries of environmental damage. source Antonio Calanni/AP

So, why is this 15th century mural still so celebrated today?

"One reason it's so famous is because its survival is something of a miracle," King said. "It's the art world's most famous endangered species. A century ago it was almost given up for lost. After its most recent restoration - something of a miracle in itself - we can appreciate its beauty. Because it is still, despite the losses, an amazingly beautiful painting."

It was almost destroyed several times.

Foto: The refectory was struck by a bomb on August 15, 1943, but the mural survived. source Wikimedia Commons

The painting has faced many perils over the years.

Wehn King Louis invaded Milan in 1499, he was tempted to cut the mural from the wall and take it home with him.

Then, due to humidity and flaking, the painting was considered totally ruined by the middle of the 16th century.

In 1796, the French came back - and this time, they represented the revolutionary French republic. The invading troops used the refectory as a base and the mural as a place to take out their anti-clerical feelings, hurling rocks at the painting and gouging out the Apostles' eyes.

That wasn't the only close call the painting had. Authorities made the baffling decision to house prisoners inside the building, the New York Times reported. In the 19th century, well-meaning individuals trying to restore the mural nearly broke it apart.

Perhaps the most dramatic incident occurred on August 15, 1943, when Allied forces bombed the refectory. Atlas Obscura reported, a protective structure had been set up beforehand. While the rest of the church was largely reduced to debris, "The Last Supper" was saved.

It got off to a rocky start ...

Foto: Da Vinci's study of horses. source Wikimedia Commons

As it turns out, da Vinci started the mural at a most inopportune time. Just a year or so before he began the project, King Louis XII of France invaded Italy.

"This was a terrible tragedy for Italy, the beginning of many decades of invasion and warfare," King said. "But on a personal level, Louis' invasion meant that Leonardo lost a commission on which he had worked for eight or ten years, an enormous bronze equestrian monument."

In wartime, bronze would be collected and melted into gun metal. Da Vinci didn't just lose money because of the war. The statue would have brought him the acclaim and artistic prestige he craved.

"He received the task of painting 'The Last Supper' as compensation," King said. "It must have seemed a poor substitute."

... and the artist felt like a masterpiece might be beyond him.

Foto: A da Vinci drawing largely believed to be a self portrait. source Wikimedia Commons

"We think of Leonardo, quite rightly, as an all-conquering genius," King said. "But in fact he had his share of disappointments and failures."

In 1494, da Vinci was 42 years old. At that point, the Renaissance man had been judged by some contemporaries to have wasted his potential.

"He had failed to finish a number of commissions, and many people found him unreliable as a result," King said. "One poet mocked him, saying that he had barely managed to finish a single picture in ten years. Leonardo was desperate to create what he called a 'work of fame' - something that would make him famous for posterity. He finally gained it with 'The Last Supper.'"

But he drew on some of his earlier work to create what is now an iconic image.

Foto: St. James the Greater reacts to Christ's assertion that he will be betrayed by someone in the room. source Wikimedia Commons

For instance, one of the Apostles is a throwback to da Vinci's earlier work.

Da Vinci was always on the lookout for interesting faces to depict. King said that one such face is reflected in the figure of James the Greater.

"He is throwing his hands outward and looking with open-mouthed astonishment at the bread and wine," King said. "There exists a beautiful drawing by Leonardo, done in red chalk perhaps as many as five years earlier, that shows that this pose was originally that of a musician playing a stringed instrument. Leonardo, who loved music, sketched the musician as he played. Then, years later, he used the sketch to create the figure of James."

And despite what many think, Mary Magdalene is probably not in the painting...

Foto: Some have argued that this feminine figure is Mary Magdalene. source Wikimedia Commons

Over the years some have alleged that the figure to Jesus' right is actually Mary Magdalene, not St. John. King said this isn't the case.

"St. John, the youngest Apostle and the 'beloved disciple' (as he calls himself), was always shown beside Christ, which is exactly where Leonardo places him," King said. "He was also always depicted as young, beardless, and often androgynous. Leonardo kept to this kind of depiction because an androgynous young man was his ideal of beauty - one that constantly recurs in his art."

King said that the disciple Mary Magdalene did sometimes appear in other Last Supper paintings.

"Fra Angelico shows her getting ready to take Communion with the Apostles in one of his frescoes in the Dominican convent of San Marco in Florence," he said. "So there would have been nothing odd, suspicious, or controversial about her appearance in a Last Supper painting. It's just that she ain't in this one."

... nor are there any hidden symbols.

Foto: King said that it's hard to decipher the significance of some of the dramatic hand gestures made by the Apostles. source Wikimedia Commons

"I'm suspicious of the idea of hidden codes and messages in Renaissance paintings," King said. "There are no doubt many things in the painting that, 500 years later, we cannot understand or appreciate, such as the hand gestures made by the Apostles. Each of them may have a specific meaning - but it's been lost to us."

That being said, it's important to remember not to take conspiracy theories and Dan Brown novels too seriously.

"I don't believe these gestures were meant to signal any secret heresies," King said. "Leonardo wanted to convey emotion and drama, not alt-Christian views. I'm sorry to disappoint, but Leonardo simply was not into obscure symbols. That is an obsession of our age, not of his. He would be quite taken aback by speculation that he was trying to conceal secret messages in his paintings."

But Da Vinci did slip some references to his own life into the mural ...

Foto: The tapestries in the painting are similar to those belonging to da Vinci's patron. source Wikimedia Commons

You can forget about secret messages and cryptic symbols, but that doesn't mean there are no interesting details tucked away in the painting.

King said that the tapestries adorning the walls are very similar to those in the castle in Milan. What's more, the Apostles are portraits of many of da Vinci's own friends and contemporaries at the Milanese court.

"So in many ways the painting is - among other things - a representation of the court of Lodovico Sforza, the work's patron," King said.

... including making Christ a pescatarian.

Foto: "The Last Supper" doesn't have meat on the menu. source Wikimedia Commons

The bread and wine shared at the Last Supper hold a special spiritual significance for Christians.

In the painting, however, da Vinci provided his subjects with some additional grub that might seem a bit odd to modern eaters: juicy slices of eel with orange garnishes.

"The meal on the table is grilled eel," King said. "Leonardo, a vegetarian, has given Christ and the Apostles a vegetarian - or rather a pescatarian - meal."

The painting represents the culmination of the career of one of the greatest artists of all time.

Foto: source Wikimedia Commons

After years of starts and stops, da Vinci finally achieved the glory he wanted in his own lifetime with "The Last Supper."

In an excerpt from his book published in the Huffington Post, King wrote about viewing the painting through the lens of the artist's overall career.

"So Leonardo, I discovered, is not just a universal genius whom we can admire as one of the finest examples humanity has ever produced," King wrote. "He is also the patron saint of perfectionists, procrastinators, unsuccessful job applicants, and exasperated second-language students. It doesn't get much more human than that."