It is hypothesised that the name Pisani is branched from the orignal Roman family name of Piso (Pisoni/Pisonis/Pisone/Pisones), which was a prominent branch of the gens Calpurnia. For example, Calpurnia Pisonis was the 3rd and final wife of Julius Caesar. Descended from Calpus the son of Numa Pompilius, second King of Rome, there are at least 50 prominent family members.

 

Like many other cognomina, the Piso name is connected with agriculture, and comes from the verb pisere or pinsere, which refers to the pounding or grinding of corn. The family first rose from obscurity during the Second Punic War, and from that time it became one of the most distinguished in the Roman state. It preserved its celebrity under the empire, and during the first century A.D. was second to the imperial family alone. Many of the Pisones bore this cognomen alone, but others bore the agnomina Caesoninus and Frugi ¹.

 

The gens Calpurnia were a Roman noble plebeian family. The first of the gens to obtain the consulship was Gaius Calpurnius Piso in 180 B.C., but from this time their consulships were very frequent, and the family of the Pisones became one of the most illustrious in the Roman state ².

 

Gaius Calpurnius Piso was a Roman senator in the 1st century. He was the focal figure in the Pisonian Conspiracy of 65 A.D., the most famous and wide-ranging plot against the throne of Emperor Nero ³.The plot signified the growing discontent among the upper social strata of the Roman state with regards to Nero's increasingly despotic leadership, and as a result is a significant event in the road towards his eventual suicide, and the chaos that followed ⁴.

 

Below is a list of well known Romans who carried the the Piso cognomen.

 

Lucius Calpurnius C. f. C. n. Piso Caesoninus, originally a member of the gens Caesonia, and adopted by one of the Calpurnii; consul in 148 B.C.
Lucius Calpurnius L. f. C. n. Piso Caesoninus, consul in 112 B.C.
Lucius Calpurnius L. f. L. n. Piso Caesoninus, manufactured arms at Rome during the Social War.
Lucius Calpurnius L. f. L. n. Piso Caesoninus, consul in 58 B.C., and father-in-law of Caesar.
Calpurnia L. f. L. n., the last wife of the dictator Gaius Julius Caesar.
Lucius Calpurnius L. f. L. n. Piso Caesoninus, consul in 15 B.C.
Lucius Calpurnius L. f. L. n. Piso Caesoninus, elder son of the consul of 15 B.C.
Lucius Calpurnius L. f. C. n. Piso Frugi, consul in 133 B.C.
[[Lucius Calpurnius Piso Frugi (propraetor circa 112 BC)|Lucius Calpurnius L. f. L. n. Piso Frugi]], propraetor in Hispania Ulterior circa 112 B.C.
Lucius Calpurnius L. f. L. n. Piso Frugi, praetor in 74 B.C., frustrated some of the schemes of his colleague, Verres.

Gaius Calpurnius L. f. L. n. Piso Frugi, quaestor in 58 B.C., married Tullia, the daughter of Cicero.
Gnaeus Calpurnius Piso, consul in 139 B.C.
Quintus Calpurnius Piso, consul in 135 B.C., sent against Numantia, but instead of attacking the city, plundered the territory of Pallantia.Calpurnius Piso, praetor circa 135, defeated during the slaves.
Calpurnius Piso, fought successfully against the Thracians circa 104 B.C.
Gaius Calpurnius Piso, consul in 67 B.C.
Gnaeus Calpurnius Piso, legate of Gnaeus Pompeius during the war against the pirates and the Mithridatic War.
Gnaeus Calpurnius Piso, one of Catiline's conspirators, propraetor in Hispania Citerior in 65 B.C.
Marcus Pupius Piso, originally one of the Calpurnii, adopted by Marcus Pupius.
Marcus Piso, praetor in 44 B.C., opposed Marcus Antonius, for which he was praised by Cicero.
Gnaeus Calpurnius Cn. f. Cn. n. Piso, a partisan of Pompeius, and subsequently of Brutus and Cassius; subsequently pardoned, and made consul in 23 B.C.
Gnaeus Calpurnius Cn. f. Cn. n. Piso, consul in 7 B.C., accused of murdering Germanicus.
Lucius Calpurnius Piso, consul in 1 B.C.
Lucius Calpurnius Piso, accused of plotting against the life of Tiberius in A.D. 24.
Lucius Calpurnius Piso, praetor in Hispania Citerior in A.D. 25
Lucius Calpurnius Cn. f. Cn. n. Piso, consul in A.D. 27.
Marcus Calpurnius Cn. f. Cn. n. Piso, the younger son of the consul of 7 B.C., accused with his father, but pardoned by Tiberius.
Gaius Calpurnius Piso, consul in A.D. 41 with the emperor Claudius, and the author of the conspiracy against Nero in A.D. 65.
Lucius Calpurnius L. f. Cn. n. Piso, consul in A.D. 57 with the emperor Nero.
Lucius Calpurnius Piso Licinianus, named heir by the emperor Galba, and murdered on the orders of Otho in A.D. 69.
Calpurnius Galerianus, son of Licinianus, murdered by Gaius Licinius Mucianus, the praefectus of Vespasian.
Calpurnius Piso, consul in A.D. 175, during the reign of Commodus.
Lucius Calpurnius Piso Frugi, a third century usurper described in the Historia Augusta.

 

^1,2 http://en.wikipedia.org/wiki/Gens_Calpurnia

³ http://en.wikipedia.org/wiki/Gaius_Calpurnius_Piso

⁴ http://en.wikipedia.org/wiki/Pisonian_conspiracy