A clearing around Porta San Gallo has existed since the fourteenth century and its name has historically been Porta San Gallo Square. In 1738 the square's triumphal arch was erected to celebrate the arrival of Lorena dynasty in Florence.
In 1865, the square was upset to crush the walls of the city, and was rebuilt with a completely new drawing by the architect Giuseppe Poggi, that since 1865 and 1875 made the odiern elliptical square, surrounded by harmonious palaces, with classical series of porches. In the middle of the square was settled a garden with fountain and a pool among Porta San Gallo and triumphal arch. Were planted many high trees that also today protect the square from the traffic of the viali di Circonvallazione that surrounds the square.