Why did Octavian, Mark Antony, and Lepidus create the Second Triumvirate?

The Second Triumvirate was formed in 43 BCE by Octavian, Mark Antony, and Lepidus to consolidate their power as the leaders of the Caesarian party following the assassination of Julius Caesar.12

After Caesar’s death, the conspirators Brutus and Cassius had seized control of eastern provinces and armies, while Mark Antony and Octavian—initially rivals—found themselves in a political stalemate. Recognizing that their respective armies would not fight one another, the three men joined forces to secure absolute authority, which was formally granted to them as triumviri rei publicae constituendae ("triumvirs for organizing the state").13

This alliance allowed them to:
* Eliminate political enemies: They secured control of Italy through massive proscriptions and confiscations, notably leading to the death of Cicero.1
* Defeat the conspirators: By combining their military resources, they successfully defeated Brutus and Cassius at the Battle of Philippi in 42 BCE.12
* Divide the Roman world: Following their victory, they partitioned the Roman territories among themselves to solidify their collective rule.41