The history of Piazza San Marco is as long and versatile as that of Venice itself. The space, currently occupied by the Piazza, was first designed for a square in the 9th Century in front of the equally famous St Mark's Basilica. After a few rearrangements of the area, the square was acquired its present size and shape in 1177. The formal occasion was the visit of Pope Alexander III and Emperor Friedrich I Barbarossa in Venice in the same year.

The most imposing buildings around Piazza San Marco are St Mark's Basilica with the Campanile and the Loggetta, St Mark's Clocktower, the Doge's Palace, the Procuratie Vecchie, the Procuratie Nuove and Biblioteca Marciana. The ground floors of some of these constructions are occupied by numerous cafes. Even the Correr Museum and the Museum of Archaeology are housed here.

A narrower part of the square, called the Piazzetta, is open to the lagoon in the mouth of Canal Grande, and hosts two of the symbols of the city: St Mark's Lion and the statue of St Theodore, the patron saint of Venice. After roughly acquiring its current appearance, Piazza San Marco was paved with bricks during the 13th Century. Five hundred years later they were removed to make room for the more stable pavement that is still intact today. Over the course of time, the large square often had the joyless destiny of being a scene for public executions.

During the French occupation at the end of the 18th and beginning of the 19th Century, Napoleon took over the Procuratie Nuove and turned it into his royal palace, adding a new wing, known today as the Napoleonic Wing. The great leader is said to have pronounced the illustrious phrase that Piazza San Marco was the finest drawing room in Europe. In spite of its unique beauty, cultural significance and tourist appeal, the most famous spot in Venice has a big problem: it is practically the lowest point of the city. This often results in floods caused by the high tide in the winter months.