The Palio di Siena is a horse race that is held twice each year, on 2 July and 16 August, in Siena, Italy. Ten horses and riders, bareback and dressed in the appropriate colours, represent ten of the seventeen contrade, or city wards. The Palio held on 2 July is named Palio di Provenzano, in honour of the Madonna of Provenzano, a Marian devotion particular to Siena which developed around an icon from the Terzo Camollia. The Palio held on 16 August is named Palio dell'Assunta, in honour of the Assumption of Mary. Sometimes, in case of exceptional events or local or national anniversaries deemed relevant and pertinent ones, the city community may decide for an extraordinary Palio, run between May and September. The last one was in year 2000, to celebrate the entering of the city in the new century. The next will be 20th October 2018, in commemoration of the Great War. A pageant, the Corteo Storico, precedes the race, which attracts visitors and spectators from around the world. The race itself, in which the jockeys ride bareback, circles the Piazza del Campo, on which a thick layer of dirt has been laid. The race is run for three laps of the piazza and usually lasts no more than 90 seconds. It is common for a few of the jockeys to be thrown off their horses while making the treacherous turns in the piazza, and indeed, it is not unusual to see unmounted horses finishing the race without their jockeys.