Julius Pomponius Laetus was born in Calabria, he was a bastard of the House of the Sanseverino of Naples, Princes of Salerno, but owing to his great admiration for antiquity and the Roman Republic he would not recognize them as connections. When very young he went to Rome and became a pupil of Valla. His brilliant capacities won him admiration and success. He wished to live the life of the ancients.
Laetus and a few kindred souls, Platina, the future librarian of the Vatican, Sabellicus, afterwards prefect of the Library of San Marco of Venice, founded a semi-pagan academy. Its members assumed Latin names. Latin recitations were done and a banquet closed every meeting. At other times, the members gave Latin farces much like the Atellanae. But Paul II, a pope who did not favour the Humanists, occupied the Chair of Peter.
Laetus was looked upon as a scorner of Christianity, sodomite and conspirator. Venice delivered him into the hands of the pope. Confined in the Castle of Sant' Angelo in 1468, he with Platina and others was tortured. However, he defended himself. On the accession of Sixtus IV (1471) Laetus was released and the academy allowed to continue its meetings.
He lectured in the Roman University. He was often seen at daybreak, descending, with lantern in hand, from his home on the Esquiline, on his way to his lectures where many eager hearers awaited him. He was a very conscientious professor, especially learned in Roman antiquities but exclusively a Latinist. He had declined to study Greek for fear of spoiling his Latin style.
His knowledge of ancient Rome was immense and his works numerous; they included a historical compendium of Roman and Byzantine emperors and a commentary on Vergil. As a tutor he exerted great influence on Alessandro Farnese, who became Pope Paul III.
He went so far as to read the most classical authors only and disdained the Bible and the Fathers. Until the last year of his life he had desired to be buried in an ancient sarcophagus on the Appian Way, but he died a Christian death in Rome. Alexander VI wished his obsequies at the church of Aracoeli to be magnificent. He was buried at San Salvatore in Lauro.