The Bassi Counts of Murena, Governors of Pisa, took up residence in Venice, after being driven away by Pepin, son of Charlemagne where they were called Pisani (meaning "from Pisa"). It was around the year 905 when the Pisani family started to build their fortune as merchants, bankers and mercenary leaders. This led them to the highest positions in the Republic, and they became one of the richest and most noble Venetian families.

Today the name thrives in Italy and has an obvious connection with close neighbour Malta, where too the name is used. The consensus is that the name came directly from Italy, a product of the travelling noble families - but there exists a school of thought that some Pisani families took their name from a more local Maltese source.

Pisani is a surname which has woven its way throughout Italy over the centuries and can now be found from North to South. The name has taken on many guises throughout history, whether it be due to poor literacy or purely regional dialectical variations, but all in all it is still instantly recognisable. While Pisano may pre-date Pisani in Italy (the name Pisani may be a directly derived from the personal name Pisano), it is still a commonly held surname today. Take a trip to Sardinia and you will find Pisanu, a throwback from the Catalan occupancy of the island some seven hundred years ago; a language that some there still speak today.

Other variations found in Italy include: PISA, PISANÒ, PISANELLO, PISANIELLO, all meaning "to come from the town of Pisa".

While Venice may be the home of some the most notable Pisani families, it is Pisa that is looked to as the true root of the vast global Pisani family. However, there are two furhter theories which suggest alternative roots to the Pisani name in some branches. One is the Maltese theory of the name deriving from the locality of Hal Pessa theory! Another theory is that the name, in some branches, is derived from the Roman gens name of Calpurnia.