The War of Actium became the final act in nearly a century of political instability in Rome. The latest war, spurred by senators assassinating the previous war's victor, Julius Caesar, in the Forum itself, had been won by the Second Triumvirate of Caesar's great-nephew and adopted son Octavian and two of his most trusted generals, Marcus Lepidus and Marcus Antonius (Mark Antony). The alliance soon collapsed with Lepidus disgraced, and Octavian sought to defeat his rival Antony, who had grown to legendary status with victories in the East. He had even taken up with Cleopatra, Julius's former love, in Egypt despite being Octavian's brother-in-law. Anthony divorced Octavia, married Cleopatra, and wrote a new will that all of his possessions would go to the children he had with Cleopatra as well as granting Julius and Cleopatra's sixteen-year-old son Caesarion huge realms to rule from the Roman conquests. Octavian stirred the senate with propaganda to declare war on Egypt to win the lands back legally. Antony and a large faction of senators took up arms in Cleopatra's support.
Much like all best-laid plans, they quickly went awry. Facing a choppy sea, Antony's large ships were barely maneuverable, especially with the plague of malaria that had reduced them to minimal rowers. Octavian brought his ships up to bottle-up Antony's fleet, and Cleopatra escaped through the gap in Octavian's lines. At first a promising wind blew to support the Egyptians, but then it abruptly turned against them. Seeing it as a sign from the gods, Cleopatra turned her ships about and attacked Octavian's fleet from the flank and behind.
Although Octavian had superior numbers, his ships were surrounded with many of them caught uselessly in the middle. Those on the outermost edges fought to a gradual standstill, and then it was Antony's battleships that won the day. They served as floating fortresses, moving slowly but surely, to annihilate ship after ship. What of Octavian's forces could escape did so, but Octavian's body was found after the battle so badly burned that it had to be recognized by Julian family amulets.
Instead of falling back to Alexandria, Antony hurried to capitalize on his surprise victory by moving on Rome itself. Many of Octavian's former allies swarmed to his side. Others felt it was best to flee, and Antony repeated his previous venture with Julius Caesar hunting down those who resisted them through Octavian's holdings in Hispania. Antony restructured Roman nobility by rewarding those loyal to him, establishing a generational dependence on the wealth of Egypt, particularly its bountiful harvests of grain that fed what essentially became a client state.
Cleopatra was hardly welcome in Rome the first time she came in 46 BC with Julius Caesar, but this time the Romans were too afraid to displease her. She soon returned to Egypt, and Egyptian culture flooded Rome with cults of Isis and Osiris. In 12 BC, Gaius Cestius completed as his burial chamber the first pyramid in Rome, one of many more to follow. Caesarion, Antony's chief heir and adopted son, was not only considered the son of deified Julius Caesar but also deified himself. Though Caesarion would only have four extended visits to Rome during his lifetime, one was to dedicate his own temple to himself on the Palatine Hill.
Instead, Caesarion dedicated his life to formalizing the new Egyptian empire. He inherited a firm hand over Rome itself as well as a sizeable personal empire that stretched from Greece to Armenia in the Donations of Alexandria that had started the War of Actium. Caesarion's half-brother Alexander Helios became ruler of Parthia through a marriage orchestrated by Mark Antony, while his half-sister, Selene, married King Juba II of Numidia and Mauretania. Caesarion dispatched his younger half-brother, Ptolemy Philadelphus, to Rome to serve as pontifex maximus and manage affairs in the northwestern side of his empire.
Egypt began a new era as a naval empire. Its western fleet roamed west of the Pillars of Hercules sailing north to Britannia for tin and south for African gold. The eastern fleet sailed for trade with India and a sea route to southern Parthia. Dreams of joining the two through a canal would require centuries to realize; until then, eastern Egypt remained the focus of the flow of goods unloading and reloading. Egyptian Thebes (once Luxor) and Antinoopolis became two of the largest cities in the world as transition sites along the Nile. Large trade fleets circumnavigated the continent of Africa, repeating the three-year journey along the route commissioned by Necho II six centuries earlier. Even after Egypt's empire splintered and fell away from rebellion and barbarian incursion, Egyptian-founded port cities still traded from Africa to Indonesia.
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In reality, Octavian won the Battle of Actium, much in thanks to Quintus Dellius deserting Antony and turning over his battle plans and Antony missing the signal from Cleopatra to retreat and misinterpreting it as a rout. Antony and Cleopatra did fall back to Alexandria, where they committed suicide after Octavian laid siege. Octavian became Pharaoh and held Egypt as a personal possession, adding it to further legal powers that established him as Augustus Caesar, the first of a long line of Roman emperors. Egyptian grain continued as a key economic force behind the emperors for centuries to come.