It was originally a large lawn on the Bisenzio, used since the 12th century to hold markets. Later it became the location of the annual September fair. The walls along the river, the Mercatale Gate and the bridge on the Bisenzio, together with the other section of walls to the east delimited the ample space giving it its particular almond shape.
Most of the buildings that stood along the Mercatale were modest dwellings and shops of artisans. In 1531 special sheds called "tiratoi" belonging to the Arte della Lana were built at the centre of the square. They were demolished then in 1783 giving new value to the New Houses built on the eastern side, typical examples of popular building of the second half of the 17th century.
The tree lined garden built in 1926 changed the configuration of the square, which was severely damaged during the bombing of 1944. Currently the square has a series of late 19th and 20th century houses, with few ruins of the original loggias under which skilled artisans, especially copper beaters, carried out their work. At the point where the square meets Via del Carmine stands the Church of San Bartolomeo, entirely rebuilt after the war.