However, civil war flared again when the Second Triumvirate of Octavian, Lepidus and Mark Antony failed. The ambitious Octavian built a power base of patronage and then launched a campaign against Mark Antony. At the naval Battle of Actium off the coast of Greece, Octavian decisively defeated Antony and Cleopatra. Octavian was granted a series of special powers including sole "imperium" within the city of Rome, permanent consular powers and credit for every Roman military victory, since all future generals were assumed to be acting under his command. In 27 BC Octavian was granted the use of the names "Augustus" and "Princeps", indicating his primary status above all other Romans, and he adopted the title "Imperator Caesar" making him the first Roman Emperor.

What failure caused the the flares of civil war to spark up again?