St. Mark’s Basilica is one of the most-visited sights in Venice, and a must-see on any traveler’s Italy itinerary! But with a history that stretches all the way back to the 9th century A.D., it’s also a church with a lot of interesting stories and legends behind it.Here are six of the most fascinating facts about St. Mark’s Basilica!

1 The basilica began with a swashbuckling tale of kidnapping

The first St. Mark’s Basilica was built on this spot in the 9th century to house very sacred relics—relics that had been stolen! In 828, merchants from Venice stole the body of St. Mark the Evangelist, one of the four Apostles, from Alexandria, Egypt. According to the legend, they snuck them past the (Muslim) guards by hiding them under layers of pork in barrels!

While at sea, a storm almost drowned the graverobbers and their precious cargo, it’s said that St. Mark himself appeared to the captain and told him to lower the sails. The ship was saved, and the merchants said they owed their safety to the miracle.

The entire story is pictured on the 13th-century mosaic above the left door as you enter the basilica.

2 There is enough mosaic to cover 1.5 American football fields!

There are more than 85,000 square feet (or 8,000 square meters) of mosaic in St. Mark’s Basilica… or enough mosaic to cover over 1.5 American football fields! The mosaics were done over 8 centuries, mostly in gold, and the result is astonishing. Enter the basilica at different times of day to see how the light makes the colors and scenes, look different.

3 There are more than 500 columns

Just another example of the sheer size, and amount of amazing stuff, in St. Mark’s Basilica is the number of columns. There are more than 500 columns and capitals in the basilica, and most are Byzantine, dating between the 6th and 11th centuries. Some classical, 3rd-century capitals are mixed in, too!

4 A lot of the basilica’s treasures came from the Crusades & from Constantinople

The Fourth Crusade, in particular, gave St. Mark’s Basilica a windfall. After all, this was the Crusade that ended, in 1204, with the conquest of Constantinople (modern-day Istanbul).

The result? A lot of treasure was shipped to Venice, and installed in St. Mark’s Basilica — including the four bronze horses, an icon of the Madonna Nicopeia, enamels of the Golden Altar-piece, relics, crosses, chalices, and patens!

5 The Pala d’Oro puts the Crown Jewels to shame

Forget the glittering gems at the Tower of London: The Royal Family has nothing on St. Mark’s Basilica! The Pala d’Oro, a Byzantine altar screen of gold, is studded with hundreds of gems – literally. They include 1,300 pearls, 300 emeralds, 300 sapphires, 400 garnets, 100 amethysts, plus rubies and topazes.

6 That bell tower? It collapsed once

The 323-foot (98.6-meter) campanile of St. Mark’s dates back to the 9th century… but it had to be rebuilt in 1903. The reason? It collapsed! It had been reworked in the 16th century, and apparently not that well.

It collapsed on July 14, 1902. (To be fair, it had survived several earthquakes before that!). Although it buried the Basilica’s balcony in rubble, fortunately, the church itself was saved. But the incident was embarrassing enough!

From 1903 to 1912, the bell tower was rebuilt exactly as it had been… except with better, safer techniques.

Ok we mentioned six, but since we’re on a roll, here are more fascinating insights:

• The gold pieces of the mosaics inside St. Mark’s Basilica are made with REAL gold!

Venice was in the past a very wealthy city of merchants: what the Republic lacked in military strength or in land domination, it had in riches. The basilica’s mosaics are not just a way to please God and St. Mark or to communicate complex religious concepts, they were also a way to show the wealth of the city to important guests, like kings or ambassadors from other countries.

The golden pieces are actually made of gold: each one has a thin gold leaf ‘sandwiched’ between two layers of clear glass. With such a display of precious material, the Venetians could show at the same time their grand devotion but also their political ‘weight’: an extremely important thing for such a small country.

• The big outer domes above the basilica are actually fake!

In Venice, it’s impossible to build huge structures: the terrain is frail, so you have to carefully stick to small, light and flexible buildings. But the Venetians had to find a way to astonish their guests: so they optimized some very clever tricks to cheat the eye and give everyone the impression that the buildings are huge and imposing.

In St. Mark’s Basilica, there is a great example of this: the five big domes that give the building its distinctive shape are just a superstructure made of wood covered with a thin layer of lead. They are actually completely empty: the brick-built domes with the mosaics that you see inside the church are much lower.

We can arguably say that the only role of those big empty domes is to make the building look much bigger than it really is: this way the ships approaching the city could recognize its shape from afar, and be even more astonished by the legendary city rising from the waters.

• In 2019, a big “acqua alta” completely flooded the church!

In the Venetian Lagoon, there are tides: sometimes these tides go higher than normal and as a result, some parts of the city get flooded. St. Mark’s Square is the lowest part of the city, so it’s pretty common to see its floor partially or totally submerged in water.

But on November 12, 2019, things went completely out of control: the tide rose so high that it reached the second-highest level ever recorded in the history of the city. The custodians of the church were unprepared for this event: the water not only flooded the antechamber of the basilica, which is at the same level as the square but also the church itself, which is much higher.

The damage was substantial and the building is still recovering: at least this tragic event gave a big push to the completion of the MOSE project, a system of mobile barriers meant to protect the Lagoon from the most dangerous tides. The barriers were tested a couple of times in 2020 and apparently, they worked fine: we all hope they will be able to protect the basilica in the future.

• St. Mark’s Basilica is not the oldest one, nor the biggest church in Venice!

The St. Mark’s Basilica was built starting from the IX century: but the history of Venice starts way before that moment, in the V-VI century. So there are churches around the city that predate the most important monument: according to historians, the oldest holy building of the city could be the church of San Giacometto, very close to the Rialto bridge. The Rialto area was, in fact, the first spot that was colonized when the islands started to be populated: the city of Venice was actually called “Rialto” for the first centuries.

Despite its enormous size, at least in proportion with the other buildings of the city,  St. Mark’s Basilica is also not the biggest church: this title goes to the church of Santi Giovanni e Paolo, home to the very powerful Dominican monastic order. Their monastery was so big that when Napoleon conquered Venice he chose that building to become the first big public hospital in the city: and the hospital is there still today! You can learn more about San Giacometto and Santi Giovanni e Paolo if you take the Welcome to Venice tour or the Venice in a Day tour, which both feature these very important churches!

Special thanks go to our Walks of Italy guide Mosè Viero for sharing these additional interesting facts about St. Mark’s Basilica. 

If you want to learn more, check out our experiences in Venice of both St. Mark’s Basilica and the Doge’s Palace—or, for a really VIP visit, access St. Mark’s Basilica after hours, when it’s closed to the public!