Final answer:
Octavian (later known as Augustus) was out to avenge his adoptive father Julius Caesar. He formed the Second Triumvirate with Mark Antony and Lepidus and eventually defeated Mark Antony to become the sole ruler of Rome.
Step-by-step explanation:
Octavius, also known as Octavian before he became Augustus, sought to avenge Julius Caesar, his adoptive father, after Caesar's assassination. Octavian navigated a complex political landscape, initially forming the Second Triumvirate with Mark Antony and Lepidus to defeat the assassins of Caesar. Despite their temporary alliance, Octavian and Antony ultimately turned against each other, culminating in Octavian's triumphant defeat of Antony and Cleopatra at the Battle of Actium in 31 BCE and his consequent rise to power as the first Roman Emperor.