"He [Caesar] had love affairs with queens too...but above all with Cleopatra, with whom he often feasted until daybreak, and he would have gone through Egypt with her in her state-barge almost to Aethiopia, had not his soldiers refused to follow him."
Suetonius, Life of Julius Caesar (LII.1)
Julius Caesar defeated Ptolemy XII on March 27, 47 BC and established Cleopatra and her brother Ptolemy XIII on the Egyptian throne. Almost as soon as his cruise on the Nile with Cleopatra had ended, he proceeded against Pharnaces II, king of Pontus, who had taken advantage of the civil war in Rome to reclaim territory lost by his father, Mithridates VI, defeating him at Zela on August 2—only five days after arriving and in a battle that lasted just four hours. The question is just how long Caesar remained at Alexandria before leaving for Pontus.
In a letter to Atticus dated July 5, Cicero, who had deserted Pompey after his loss at Pharsalus, writes that he heard a rumor that Caesar had left the city (Letters, CDXXXIV [XI.25.2]). The month before, on June 19, Cicero still despaired of any knowledge about Caesar's departure—83 days after his victory over Ptolemy (CDXXXII [XI.18.1]). If the same amount of time was required to report news of Caesar leaving Egypt, it would have occurred about April 10, two weeks after the Battle of the Nile. Hirtius, the other primary source, speaks in the Bellum Alexandrinum (XXXIII.4) of the time between the establishment of Cleopatra and Caesar's departure as being "within a few days," which Lord understands to mean not more than a month and perhaps as little as two weeks, i.e., sometime between the middle and end of April. Calculating the time it would take to travel to Zela, he concludes that Caesar could not have left Alexandria later than May 5, 38 days after his victory over Pharnaces.
Writing almost two centuries after the events he describes, Appian is the only other ancient authority to speak of the sojourn of Caesar and Cleopatra. "He made a voyage on the Nile to look at the country with a flotilla of 400 ships in the company of Cleopatra, and enjoyed himself with her in other ways as well" (The Civil Wars, II.90; also Dio, Roman History, XLII.45.1 "She would have detained him even longer in Egypt"). No more contemporary sources mention the cruise, however, and, given the relatively brief time Caesar remained in Alexandria, it is possible that the voyage did not occur at all or was only of short duration.
It is unlikely that the royal barge ever was used by Cleopatra, however, as Athenaeus concludes by saying that the wealth of Egypt had been dissipated by her father Ptolemy XII Auletes ("flute-player"), leaving little money by the time she ascended the throne (The Deipnosophists, V.206D). Indeed, Cleopatra did not even mint any gold coins.
The mosaic is from Palestrina (ancient Praeneste, just east of Rome) and now in the Staatliche Antikensammlungen (Berlin), where it is placed between the busts of Caesar and Cleopatra. It is part of another, larger Nilotic mosaic dating to the late first century BC found at the Temple of Fortuna Primigenia in Palestrina and in the National Archeological Museum there. Given the Egyptian topography and Alexandrian origin of the work (animals familiar to the Alexandrians have no labels; those that are not, such as giraffes and rhinoceroses, are in Greek), it has been suggested that the mosaic may have been commissioned by Cleopatra, herself, to thank the goddess Primigenia for the birth of Caesarion.
This bust of Caesar is of green Egyptian basanite and also is in the Staatliche Antikensammlungen, where it is paired with that of Cleopatra. It likely dates from the first half of the first century AD, some fifty or more years after Caesar's assassination. In marked contrast to his much younger lover, an old man is portrayed, gaunt and with thinning hair and pronounced lines around the bridge of the nose and eyes (the insets of which are a later addition).
Caesar reported the Battle of Zela to the Senate with the words Veni Vedi Vici—"I came, I saw, I conquered." He was sufficiently pleased with the phrase that he had it inscribed on a placard (titulus) for his triumph, "not indicating the event of the war, as others did, but the speed with which it was finished" (Suetonius, Life of Julius Caesar, XXXVII.2). Suetonius is the only author to give the original Latin phrasing. Plutarch, who comments on its "brevity which is most impressive" (Life of Julius Caesar, L.3–4) and Appian (The Civil Wars, II.91) both say that the words were sent to Rome—but they wrote in Greek.
The placard carried in Caesar's triumph is exceptional as well in that it is the only instance in which a titulus does not identify or describe captives or spoils of war but, in the first person singular, the triumphator himself, a man proud to have so readily defeated the son of Mithridates VI—whom Sulla, Lucullus, and Pompey had fought for a quarter of a century in three interminable Mithridatic Wars.
In terms of rhetorical devices, this laconic dispatch represents alliteration (repetition of the same sound), asyndeton (the omission of conjunctions between clauses), parechesis (the repetition of the same sound in succession), tricolon (verbs of the same length), hyozeuxis (each clause having its own verb), and parallelism (similarity of structure in a series of related words).
References: The Letters of Cicero (1899-) translated by Evelyn S. Shuckburgh; "The Date of Julius Caesar's Departure from Alexandria" (1938) by Louis E. Lord, The Journal of Roman Studies, 28(Pt 1), 19-40; "The Nile Cruise of Cleopatra and Caesar" (2002) by T. W. Hillard, The Classical Quarterly, 52(2), 549-554; Appian: The Civil Wars (1996) translated by John Carter (Penguin Classics); Cleopatra of Egypt: From History to Myth (2001) edited by Susan Walker and Peter Higgs (exhibition catalog); "VENI VIDI VICI and Caesar's Triumph" (2013) by Ida Östenberg, The Classical Quarterly, 63(2), 813-827.
See also Mithridates VI.