A grandnephew of Servius Sulpicius Rufus, he was also a nephew or great-grandson of Gaius Cassius Longinus, one of Caesar's assassins.
[1] Longinus was suffect consul of the second half of the year 30 as the colleague of Lucius Naevius Surdinus.
[2] Cassius, a pupil of Sabinus, was head of the legal school called the Sabinians or Cassinians.
His principal works are the libri (commentarii) iuris civilis in at least ten volumes, which only survive in quotes by later authors such as Iavolenus.
He also conceded it violated the rights of private interests but justified it on the grounds of the public good.