The square takes its name from the Church of San Paolo, or San Polo, built here in the 9th century. This large square had a canal running alongside it that was filled in in 1700. Here, markets, festivals and football games used to be held, as were military parades and bullfights.
Lorenzino de’ Medici and his uncle Alessandro Soderini were murdered in this square. Lorenzino murdered Alessandro De' Medici in Florence in 1537 and a bounty was put on his head by Duke Cosimo, Alessandro’s successor. De Medici fled to Constantinople, Paris, and finally Venice where he lived in a palazzo in the square under the assumed name of Dario. After tracking him for a long time, two assassins hired by Cosimo intercepted him and his uncle as they left the house, stabbing them both to death, then fled, assisted by some of the noblemen of the Venetian Republic. In addition to the church and its bell tower, the square is also home to several palazzi, including Palazzo Bernardo, Palazzo Soranzo, part of Palazzo Donà and Palazzo Corner Mocenigo, and a classic well head. o

Some of the walls bear coats of arms in relief and a variety of paterae including saints, country scenes and baptism:

while the bell tower bears two lions, one with a snake around its neck, and the other holding a human head in its claws. According to tradition, they commemorate the tragic end of Marin Faliero or the Count of Carmagnola, although many believe they date from well before these men.