Horse races known as the Corso del Palio are held in its central Piazza del Campo, which is also the location of a large Public Palace which contains the Gaia Fountain and some notable frescoes depicting the effects of good government.  
One of the most important medieval natives of this city was Vannoccio Biringuccio, whose On Pyrotechnics is the first modern work on metallurgy.  This city won a major victory when Bocca degli Abati treacherously cut off the hand of his own army's standard bearer, after which their army triumphed at Montaperti.  After the assassination of Niccolo Borghese, this city was controlled by Pandolfo Petrucci, who was forced to flee after becoming involved in a plot against Cesare Borgia.  Horse races known as the Corso del Palio are held in its central Piazza del Campo, which is also the location of a large Public Palace which contains the Gaia Fountain and some notable frescoes depicting the effects of good government.  FTP, name this Tuscan city which was said to have been founded by Romulus's nephew Senius, a long-time rival of Florence whose famous natives include Duccio and Saint Catherine.
One of the most important medieval natives of this city was Vannoccio Biringuccio, whose On Pyrotechnics is the first modern work on metallurgy.  
Siena