The Pisani are an ancient Venetian patrician family. The news around the origin of the family are you, and in any case they are based on traditions and never on certain facts. A first hypothesis makes them come from the Bass counts (according to others it was the Luxi) of Pisa and, arrived in Venice in 905 (or in 804), it was called Pisani from the place of origin. Another theory, while accepting a relationship with the Tuscan city, relates them to the Romans Calpurni Pisoni.
It had an important role between the twelfth century and the beginning of the XIIIth century in the historical, political and economic events of the Republic of Venice.
Over time different branches of the family distinguished themselves from the parish of residence: San Marco, Santo Stefano (the most prestigious), Santa Maria del Giglio, San Polo, San Vitale, Santa Marina. From the mid-eighteenth century the sons of St. Stephen's branch of the Pisani house were all called Ermolao or Almorò, as a sign of devotion to Sant 'Ermolao, buried in the parish of the family, the church of San Simeon Grando in Venice. At the end of the 800 with Almorò III (1815-1880) the main male line, that of the Pisani di Santo Stefano, became extinct.