leading Optimate (conservative senator) and an uncompromising opponent of Julius Caesar (Caesar, Julius). As consul, Marcellus attempted to remove Caesar from his army command on March 1, 50, but he was outmaneuvered by the pro-Caesarian tribune Gaius Scribonius Curio. During the Civil War (Caesar against Pompey the Great and the majority of the Senate, 49–45) Marcellus followed Pompey to Greece; after Pompey's defeat at Pharsalus in 48 he retired to Mytilene, where he practiced rhetoric and studied philosophy. In 46 the Senate successfully appealed to Caesar to pardon Marcellus. It was to celebrate the pardon that Cicero delivered his speech Pro Marcello. Marcellus left for Italy but was murdered in Piraeus, Achaea, by one of his own attendants. The rumours that Caesar had engineered the assassination were not believed by Cicero (Letters to Atticus).

Roman general who captured Syracuse during the Second Punic War (218–201). Although his successes have been exaggerated by the historian Livy, Marcellus deserved his sobriquet, “the sword of Rome.”

In his first consulship (222) Marcellus fought the Insubres and won the spolia opima (“spoils of honour”; the arms taken by a general who killed an enemy chief in single combat) for the third and last time in Roman history. He relieved the Roman garrison at Clastidium (modern Casteggro) and captured Mediolanum (modern Milan). After the Roman defeat at Cannae (216), he commanded the remnant of the army at Canusium and saved Nola and southern Campania from Hannibal. From 214, when he was consul for the third time, to 211 he served in Sicily, where he stormed Leontini and, after a two-year siege, took Syracuse. His troops killed the great scientist Archimedes and sacked the city, while Marcellus carried its art treasures to Rome. Marcellus was consul again in 210 and took Salapia in Apulia, which had revolted and joined forces with Hannibal. In 209 he fought Hannibal inconclusively near Venusia. In his fifth consulship (208) he was killed in an ambush while reconnoitering enemy positions.

nephew of the emperor Augustus (reigned 27 BC–AD 14) and presumably chosen by him as heir, though Augustus himself denied it.

Marcellus was the son of Gaius Claudius Marcellus and Augustus's sister Octavia. In 25 he and the future emperor Tiberius served under Augustus in Spain. That same year he was married to the emperor's daughter Julia, an event that seemed to mark him as heir. His ambitions brought him into conflict with Agrippa, but he died two years later. At the time of his death, he was a curule aedile, a magistrate's office that he held at a younger age than normal and that he celebrated with exceptionally magnificent games. Great hopes had been built on him, and he was celebrated by many writers, especially by Virgil in a famous passage in the Aeneid and in Propertius. He was buried in the mausoleum of Augustus, and Augustus himself pronounced the funeral oration. Octavia built a library in his honour, while Augustus named a theatre after him, the remains of which were standing in the 21st century.