Florence's first dramatic society, the Accademia degli Immobili was founded in 1644 by Principe Don Lorenzo de’ Medici and met on this street, then called Via del Cocomero ('Watermelon Street') although it soon broke up into two factions. The Immobili founded the Teatro della Pergola, while the faction that remained here changed their name to the Accademia degli Infuocati, whose symbol was a lit bomb and whose motto was A tempo infuocati ('A Fiery time'). It's still there, over the door.
Throughout the 1700s, the theatre was enlarged with tiers (similar to its rival, the Pergola) and reformed into the classic Italian horseshoe shape. It was called the Teatro del Cocomero 'of the Watermelon') until 1860, when it took the name Niccolini from its impresario. In the 1970s it was used as a cinema, then fell into disuse until recently: in 2006 it was purchased and restored to its original glory and reopened in 2016, for plays and musicals.
Image by Manuelarosi, Creative Commons License