After several years of triumvirate, now master of the west, Octavian decided to wage war against Antony; however, he did not declare war directly against him, but against Cleopatra, reading the triumvir’s will in the senate: “His alliance with Antony had always been doubtful and unstable, while their continual reconciliations were nothing more than momentary accommodations; at last they came to a final rupture, and in order better to show that Antony was no longer worthy to be a Roman citizen, he opened his will, which Antony had left in Rome, and read it before the assembly, where he also designated as his heirs the children he had had by Cleopatra. ” (Suetonius, Augustus, 17)
Suetonius narrates that Antony would answer him indignantly, ” What has changed you? The fact that I mate with a queen? She is my wife. Is it not nine years that he began [our love affair]? And you only mate with Drusilla? And so you will be well if when you read this letter, you have not mated with Tertullia, or Terentilla, or Rufilla, or Salvia Titisenia or all of them. Does it profit where and with whom you mate?” (Suetonius, Augustus, 69)
The final battle took place at Actium on September 2, 31 B.C.; despite numerical and naval superiority, Antony and Cleopatra’s fleet was defeated by Agrippa. The queen and the triumvir abandoned the rest of the fleet, returning to Egypt.
On August 1, 30 B.C. Octavian entered Alexandria and Antony decided to commit suicide, followed shortly by Cleopatra.