As the largest square in the city and the only one given the designation of “Piazza” (the others are all referred to as “Campi”), St. Mark’s Square has always been the location of important government buildings and other facilities central to the goings on in Venice.

A remark usually attributed (though without proof) to Napoleon calls the Piazza San Marco “the drawing room of Europe”.
Piazza San Marco was constructed in the ninth century as a small square dotted with trees. The square was laid out in front of the original St. Mark’s Basilica, at the time a small chapel which was part of the Doge’s Palace.
Life has revolved around this piazza since the days of the Republic, when it was a market as well as the center of civic and religious life. Considered one of the finest squares in the world and certainly Venice’s prime attraction, it is surrounded on three sides by the stately arcades of public buildings and on the fourth, by Basilica di San Marco’s riot of domes, arches and the soaring St. Mark’s campanile. Several of Venice’s major sights are located here, so the square is often crowded with tourists.