The Palio di Siena is a competition between the Contrade of Siena in the form of an equestrian tournament of medieval origin. The "career", as the race is traditionally called, normally takes place twice a year: on 2 July the Palio is run in honor of the Madonna of Provenzano, the feast of the Visitation in the extraordinary form, and on 16 August the one in honor of the Madonna Assumed. On the occasion of exceptional events, city or national anniversaries deemed relevant and pertinent (for example: the centenary of the unification of Italy), the Sienese community may decide to hold an "extraordinary Palio".