How did personal relationships-between Marc Antony and Octavian and between Marc Antony and Cleopatra-affect the history of the Roman Empire?

Mark Antony and Octavian were locked in a power struggle and Octavian used Cleopatra as an excuse for war. The two men fought a propaganda war. Antony accused Octavian of being a social upstart, of forging his adoption by Caesar and of usurping power. Octavian accused Antony of treason, that he kept the provinces in the east while according to tradition it should be allocated by lots, and that he started wars against Armenia and Parthia without the consent of the Senate. He also capitalised on Antony's Donations of Alexandria. In these, he ceded much of Rome's territory in the east to Cleopatra. Cleopatra and Caesarion (the sons of Cleopatra and Caesar) were crowned co-rulers of Egypt and Cyprus and areas of the eastern part of the Roman Empire were given to Cleopatra's two other sons and her sister. Cleopatra took the title of Queen of Kings and Caesarion took the title of King of Kings. He also attacked Mark Antony when he married Cleopatra before he divorced his wife. He also disclosed information which suggested that Antony was planning to create a second Senate in Alexandria (Egypt).
Finally, Octavian summoned the Senate and accused Antony of anti-Roman sentiments. He had stolen Antony's will which recognized Caesarion as Caesar's legal heir and left his possessions to his children by Cleopatra. It also mentioned his desire to be buried with Cleopatra in Alexandria. The Senators were outraged about his desire to be buried outside of Rome. Octavian blamed Cleopatra and not Antony and the Senate declared war on Cleopatra. He used Cleopatra as an excuse to wage war on Mark Antony as he knew that he would help her. Octavian defeated the two of them and then became Rome's first emperor under the name of Augustus.